US20020122420A1 - Method and system for connectionless communication in a cell relay satellite network - Google Patents
Method and system for connectionless communication in a cell relay satellite network Download PDFInfo
- Publication number
- US20020122420A1 US20020122420A1 US09/938,923 US93892301A US2002122420A1 US 20020122420 A1 US20020122420 A1 US 20020122420A1 US 93892301 A US93892301 A US 93892301A US 2002122420 A1 US2002122420 A1 US 2002122420A1
- Authority
- US
- United States
- Prior art keywords
- packet
- cell
- cells
- segments
- relay satellite
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- 238000000034 method Methods 0.000 title claims abstract description 31
- 238000004891 communication Methods 0.000 title claims abstract description 28
- 210000004027 cell Anatomy 0.000 description 170
- 238000010586 diagram Methods 0.000 description 7
- 238000012546 transfer Methods 0.000 description 4
- 230000005540 biological transmission Effects 0.000 description 3
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 235000010627 Phaseolus vulgaris Nutrition 0.000 description 1
- 244000046052 Phaseolus vulgaris Species 0.000 description 1
- 238000005538 encapsulation Methods 0.000 description 1
- 239000012634 fragment Substances 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 230000011664 signaling Effects 0.000 description 1
- 210000001057 smooth muscle myoblast Anatomy 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/14—Relay systems
- H04B7/15—Active relay systems
- H04B7/185—Space-based or airborne stations; Stations for satellite systems
- H04B7/18578—Satellite systems for providing broadband data service to individual earth stations
- H04B7/18582—Arrangements for data linking, i.e. for data framing, for error recovery, for multiple access
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04Q—SELECTING
- H04Q11/00—Selecting arrangements for multiplex systems
- H04Q11/04—Selecting arrangements for multiplex systems for time-division multiplexing
- H04Q11/0428—Integrated services digital network, i.e. systems for transmission of different types of digitised signals, e.g. speech, data, telecentral, television signals
- H04Q11/0478—Provisions for broadband connections
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L12/00—Data switching networks
- H04L12/54—Store-and-forward switching systems
- H04L12/56—Packet switching systems
- H04L12/5601—Transfer mode dependent, e.g. ATM
- H04L2012/5603—Access techniques
- H04L2012/5604—Medium of transmission, e.g. fibre, cable, radio
- H04L2012/5608—Satellite
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L12/00—Data switching networks
- H04L12/54—Store-and-forward switching systems
- H04L12/56—Packet switching systems
- H04L12/5601—Transfer mode dependent, e.g. ATM
- H04L2012/5638—Services, e.g. multimedia, GOS, QOS
- H04L2012/5645—Connectionless
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L12/00—Data switching networks
- H04L12/54—Store-and-forward switching systems
- H04L12/56—Packet switching systems
- H04L12/5601—Transfer mode dependent, e.g. ATM
- H04L2012/5638—Services, e.g. multimedia, GOS, QOS
- H04L2012/5646—Cell characteristics, e.g. loss, delay, jitter, sequence integrity
- H04L2012/5652—Cell construction, e.g. including header, packetisation, depacketisation, assembly, reassembly
Definitions
- the present invention generally relates to cell relay satellite communication networks, and more particularly, to connectionless cell relay satellite networks.
- connection-oriented cell relay networks such as Asynchronous Transfer Mode (ATM) networks
- IP Internet Protocol
- the network In a connection-oriented network, the network must establish a connection (called a virtual circuit) between two nodes in the network with a signaling protocol before any information transfer can take place between the two nodes.
- the network Once the network establishes the connection between the two nodes, the network can identify and route the cells transmitted by the two nodes through the network.
- the existing cell relay networks must establish a connection between a source node and a destination node in the cell relay networks in order to transport IP traffic over the cell relay networks.
- satellite-based cell relay networks offer certain advantages over terrestrial cell relay networks.
- a satellite-based cell relay network can provide rapid deployment of communication services over a wide geographical area, including remote, rural, urban, and inaccessible areas.
- satellite-based cell relay networks offer more flexibility in configuring a network and allocating capacity to different sites.
- connection-oriented cell relay satellite networks have two significant disadvantages when transporting packet-based traffic from the existing networks.
- the connection-oriented cell relay satellite network must establish a connection between a source node and a destination node before any information transfer can take place between the source node and the destination node, and as a result, the information transfer will experience an initial delay due to the connection setup phase.
- the satellite network must assign a unique identifier to each connection and manage the assignment of the identifiers so that the network can efficiently reuse each identifier when establishing a new connection.
- a satellite footprint typically covers a wide geographical area, which may include large number of users, and thus, requires a large number of corresponding connection identifiers to support the users.
- each communication with, for example, a geosynchronous satellite typically experiences a 500 milliseconds round trip delay, which increases the delay due to the connection setup phase.
- the present invention comprises a method and system for communicating a packet over a cell relay satellite network, without establishing a connection in the cell relay satellite network, by dividing the packet into a number of segments at a source node in the communications network, generating for each segment a fixed size cell that includes a cell header and a payload, with a prefix, a downlink beam locator, and a source node identifier inside each cell header, inserting each of the segments into the payload of each of the generated cells, respectively, and transmitting the cells to the cell relay satellite.
- the cell relay satellite receives each transmitted cell from the source node, and broadcasts each cell on a downlink beam corresponding to the downlink beam locator in each cell header.
- a destination node in the cell relay satellite network receives each broadcasted cell on the downlink beam, and re-assembles the packet from the segments inside the payloads of the received cells. Specifically, the destination node re-assembles the packet by identifying the cells corresponding to the packet, and appending the segments inside the payloads of the identified cells together in the order of receipt of the identified cells. Finally, the destination node may identify a destination address in the packet, and may route the packet to the identified destination address, which may reside in another communications network.
- Methods and systems consistent with the present invention have two notable advantages over the existing cell relay satellite networks: First, a cell relay satellite network consistent with the present invention does not need to establish a connection in the network, and thus, eliminating the initial connection setup delay in the existing cell relay networks. Second, a cell relay satellite network consistent with the present invention does not need to expend valuable network processing resources for managing the assignment of unique identifiers to connections in the network.
- FIG. 1 illustrates a cell relay satellite network in which systems and methods consistent with the invention may be implemented
- FIG. 2 illustrates a block diagram of a node in a cell relay satellite network in which systems and methods consistent with the invention may be implemented;
- FIG. 3 illustrates a block diagram of a cell in a cell relay satellite network when using systems and methods consistent with the invention
- FIG. 4 illustrates a block diagram of a packet, which a node in a cell relay satellite network may communicate through the cell relay satellite network when using systems and methods consistent with the invention
- FIG. 5 illustrates a block diagram of a packet, which a node in a cell relay satellite network may communicate through the cell relay satellite network when using systems and methods consistent with the invention
- FIG. 6 illustrates a flow chart of the steps that a node performs to segment a packet into one or more cells for transmission in a cell relay satellite network when using systems and methods consistent with the invention
- FIG. 7 illustrates a flow chart of the steps that a destination node performs to reassemble a packet from one or more cells in a cell relay satellite network when using systems and methods consistent with the invention.
- Methods and systems consistent with the present invention communicate a packet over a cell relay satellite network, without establishing a connection in the cell relay satellite network, by dividing the packet into one or more segments at a source node in the cell relay satellite network. For each segment, the source node generates a fixed size cell that includes a cell header and a payload. The source node includes in each cell header a prefix, a downlink beam locator, and a source node identifier, and inserts the segments into the payloads of the generated cells respectively. The source node then transmits the cells on an uplink beam to the cell relay satellite.
- the cell relay satellite receives each transmitted cell on the uplink beam from the source node.
- the cell relay satellite reads the downlink identifier in each cell header, and identifies a downlink beam corresponding to the downlink beam locator.
- the cell relay satellite then broadcasts each cell on the identified downlink beam to a destination node within the footprint of the beam in the cell relay satellite network.
- the destination node receives each broadcasted cell on the downlink beam, and re-assembles the packet from the received cells. Specifically, the destination node identifies the cells corresponding to the packet, and appends the identified segments inside the payloads of the identified cells together in the order of receipt of the identified cells. Finally, the destination node may identify a destination address in the packet, and may route the packet to the identified destination address, which may reside in another communications network.
- FIG. 1 illustrates a cell relay satellite network 110 in which systems and methods consistent with the invention may be implemented.
- Cell relay satellite network 110 comprises cell relay satellites 150 a through 150 d , and satellite node terminals 100 a through 100 f .
- Cell relay satellite 150 a communicates with cell relay satellites 150 b and 150 d via beams 155 a and 155 d , respectively.
- Cell relay satellite 150 b communicates with cell relay satellite 150 c via beam 155 b
- cell relay satellite 150 c communicates with cell relay satellite 150 d via beam 155 c.
- Nodes 100 a through 100 f may include earth station terminals, for example, very small aperture terminals (VSAT), which communicate with each other through cell relay satellites 150 a through 150 d .
- VSAT very small aperture terminals
- nodes 100 a through 100 c are in the beam footprints of cell relay satellite 150 a
- node 100 d is in the beam footprint of cell relay satellite 150 b
- nodes 100 e and 100 f are in the beam footprint of satellite 150 d .
- Nodes 100 a through 100 f communicate with their respective cell relay satellites 150 a through 150 d via uplink and downlink beams.
- Nodes 100 a and 100 e interface with a packet-based communications network, for example, Internet Protocol (IP) network 120
- nodes 100 b and 100 d interface with a different packet-based communications network, for example, IP network 130
- IP Internet Protocol
- Nodes 100 g through 100 j which are not in the beam footprint of cell relay satellites 150 a through 150 d , also interface with IP network 130
- nodes 100 k through 100 m which are not in the beam footprint of cell relay satellites 150 a through 150 d , interface with IP network 120 .
- Nodes 100 g through 100 m may include, for example, desktop computers, servers, telephone sets, facsimile machines, and video apparatus.
- Nodes 100 g through 100 j may communicate with nodes 100 k through 100 m via satellite cell relay network 110 .
- node 100 k may generate information, for example, voice, data, and/or video, in form of packets, which node 100 k transmits through IP network 120 to a node that interfaces IP network 120 , for example, node 100 a .
- Node 100 a then segments the packets into one or more segments, insert each segment into payload of a cell, and transmits the cells through cell relay satellite 150 a to node 100 b .
- Node 100 b then reassembles the packets from the cells and routes the assembled packets through IP network 130 to a destination node, for example, node 100 j , whose address is specified in the packets.
- FIG. 2 illustrates a block diagram of a node, for example, node 100 a , in cell relay satellite network 110 .
- Node 100 a comprises a processor 200 , a memory 210 , a secondary storage 220 , a network interface card 230 , a transmitter 250 , a receiver 260 , an antenna 270 , and links 255 and 265 , all of which are connected together via a bus 240 .
- Memory 210 includes Packet Converter 212 , Packet Reassembler 214 , and IP Protocol Module 216 , all of which include data and/or instructions that processor 200 executes.
- Packet Converter 212 generally segments a packet into one or more segments and inserts each segment into a cell.
- Packet Reassembler 214 generally reassembles a packet from one or more cells, each including a segment of the packet.
- IP Protocol Module 216 generally includes Internet Protocol (IP), for example, IP version 4, for communicating packets through IP network 120 .
- IP Protocol Module 216 drives Network interface card (NIC) 230 for transmitting and receiving packets through IP network 120 .
- NIC 230 may include hardware and/or firmware for transmitting and receiving packets from IP network 120 .
- Secondary storage 220 comprises computer readable medium such as a disk drive and a tape drive. From the tape drive, software and data may be loaded onto the disk drive, which can then be copied into memory 210 . Similarly, software and data in memory 210 may be copied onto the disk drive, which can then be loaded onto the tape drive.
- Transmitter 250 connects to antenna 270 via link 255 .
- Transmitter 250 may include a codec and a frequency up converter for transmitting cells via antenna 270 to cell relay satellite 150 a .
- Receiver 260 connects to antenna 270 via link 265 .
- Receiver 260 may include a codec and a frequency down converter for receiving cells via antenna 270 from cell relay satellite 150 a.
- FIG. 3 is a block diagram of a cell for use in cell relay satellite network 110 in accordance with an implementation of the invention.
- cell 300 includes a cell header 310 portion and a payload 320 portion.
- Cell header 310 has a length of H bytes
- payload 320 has a length of P bytes.
- Cell 300 may be of any fixed length, for example, 53 bytes, where cell header 310 may have a length of, for example, 5 bytes and payload 320 may have a length of, for example, 48 bytes.
- cell 300 may be of any other fixed length, with any combination of cell header 310 length and payload 320 length, as a particular length for each is not essential to the practice of the present invention.
- cell header 310 includes prefix 330 , downlink beam locator 340 , source node identifier 350 , and suffix 360 .
- Prefix 330 has a fixed length of K bits; downlink beam locator 340 has a fixed length of M bits; node identifier 350 has a fixed length of N bits; and suffix 360 has a fixed length of J bits.
- prefix 330 may have a length of 6 bits; downlink beam locator 340 may have a length of 9 bits; node identifier 350 may have a length of 20 bits; and suffix 360 may have a length of 5 bits.
- prefix 330 , downlink beam locator 340 , node identifier 350 , and suffix 360 may be of any combination of lengths, as a particular length for each is not essential to the practice of the present invention.
- the first 2 bits of prefix 330 may identify the particular protocol, for example, IP version 4, for handling a re-assembled packet.
- the next 3 bits of prefix 330 may identify the handling instructions within the particular protocol, for example, the relative priority level within IP version 4.
- the last bit of prefix 330 may, identify the type of payload 320 in cell 300 , for example, whether payload 320 includes the last segment of the packet or other segments of the packet. For example, if payload 320 includes the last segment of the packet, the last bit of prefix 330 is set to “1.” Otherwise, the last bit of prefix 330 is set to “0.”
- Downlink beam locator 340 may identify a particular downlink beam in a cell relay satellite, for example, cell relay satellite 150 a , on which cell 300 may be transmitted to a destination node.
- the first 2 bits of downlink beam locator 340 may identify cell relay satellite 150 a
- the remaining bits in downlink beam locator 340 may identify a particular downlink beam in cell relay satellite 150 a on which cell 300 may be transmitted.
- downlink beam locator 340 may include a key or pointer, which cell relay satellite 150 a must translate in order to identify the corresponding downlink beam.
- Node identifier 350 may identify a source node, for example, node 100 a that initiated transmission of cell 300 .
- Suffix 360 may include a cell header error check (HEC) for error checking cell header 310 .
- HEC cell header error check
- FIG. 4 illustrates a block diagram of packet 400 , which node 100 a in cell relay satellite network 110 communicates in accordance with an implementation of the invention.
- Packet 400 includes a packet header 410 portion and data 420 portion.
- Packet header 410 may have a variable length of I bytes.
- Data 420 may have a variable length of T bytes.
- packet header 410 may include, for example, a version, header length, type of service, total packet length, packet identification, flags, fragment offset, time to live, protocol identifier, packet header checksum, source node address, destination node address, and other IP protocol options.
- packet header 410 may include any other combination of fields, as the particular format and types of information in packet header 410 are not essential to the practice of the present invention.
- a node in cell relay satellite network 110 may receive from another node, for example node, 100 k , packet 400 with packet header 410 specifying destination node address of, for example, node 100 g , which interfaces IP network 130 .
- NIC 230 receives packet 400 from IP network 120 , and stores packet 400 in memory 210 via bus 240 .
- NIC 230 then generates an interrupt signal in processor 200 , and provides the address of packet 400 stored in memory 210 to Packet Converter 212 .
- FIG. 6 illustrates a flow chart of the steps that Packet Converter 212 in node 100 a performs to segment packet 400 into one or more cells for transmission in cell relay satellite network 110 in accordance with an implementation of the invention.
- Packet Converter 212 receives from NIC 230 the memory address of packet 400 in memory 210 (step 600 ).
- Packet Converter 212 reads the destination node address in packet header 410 (step 610 ).
- Node 100 a then identifies a downlink beam in cell relay satellite network 110 for routing packet 400 to node 100 g (step 620 ).
- Packet Converter 212 identifies the downlink beam locator by referencing, for example, a stored routing table whose entry maps a destination node address, for example, node 100 g , to a particular downlink beam locator in cell relay satellite network 110 .
- the stored routing table may be generated by, for example, IP Protocol Module 216 .
- Packet Converter 212 then segments packet 400 into fixed size segments of, for example, 48 bytes (step 630 ).
- Packet Converter 212 may prepend header 510 portion, and append null padding 530 portion and trailer 520 portion to packet before segmenting packet 400 .
- Header 510 may have a length of R bytes.
- Trailer 520 may have a length of L bytes.
- Packet Converter 212 may determine the length of null padding 530 to be such that the combined length of packet 400 , header 530 , trailer 420 , and null padding 530 becomes a multiple integer of the length of payload 320 in cell 300 . This combined length may be determined as follows:
- null padding 530 length may be determined as follows:
- null padding length combined length ⁇ T ⁇ I ⁇ R ⁇ L.
- packet 400 may have a length of, for example, 500 bytes, and cell payload 320 may have a length of, for example, 48 bytes.
- Header 510 may have a length of 8 bytes, and may include, for example, the identifier “0xAA-AA-03-00-00-00-08-00,” disclosed in “Multiple-Protocol Encapsulation Over AAL5,” Internet Engineering Task Force, RFC 1483.
- Trailer 520 may also have a length of 8 bytes, whose first 2 bytes represent the length of packet 400 , the second 4 bytes include a cyclical redundancy code (CRC) for error checking, and the last 2 bytes are null.
- CRC cyclical redundancy code
- Packet Converter 212 segments the appended and prepended packet 500 into fixed size segments of 48 bytes.
- Packet Converter 212 then creates cell header 310 for each packet segment (step 640 ), and prepends cell header 310 to each packet segment (step 650 ). Specifically, in the cell header 310 prepended to the each segment, Packet Converter 212 sets the first 2 bits of prefix 330 to identify the particular protocol, for example, IP version 4, for handling the reassembled packet. Packet Converter 212 then sets the next 3 bits of prefix 330 to identify the relative priority level within IP version 4. Finally, Packet Converter 212 sets the last bit of prefix 330 to identify the type of payload 320 in cell 300 , for example, whether payload 320 includes the last segment of packet 400 or other segments of the packet. If cell header 310 is prepended to the last segment of packet 400 , Packet Converter 212 sets the last bit of prefix 330 to “1.” Otherwise, Packet Converter 212 sets the last bit of prefix 330 to “0.”
- Packet Converter 212 sets downlink beam locator 340 in each cell header 310 to the downlink beam identifier that Packet Converter 212 identified in step 620 . Furthermore, Packet Converter 212 sets node identifier 350 in each cell header 310 to the address of node 100 a . Packet Converter 212 calculates a header error check (HEC) and includes the HEC in suffix 360 of each cell header 310 . Finally, Packet Converter 212 generates an interrupt signal in processor 200 , and provides the address of each completed cell in memory 210 to transmitter 250 . Transmitter 250 then transmits each cell in order starting with the cell that includes the first packet segment and ending with the cell that includes the last packet segment through antenna 270 and via an uplink beam to cell relay satellite 150 a.
- HEC header error check
- Cell relay satellite 150 a receives each cell 300 at an input port, which receives the uplink beam.
- Cell relay satellite 150 a then reads downlink beam locator 340 in each cell header 310 , and identifies an output port corresponding to downlink beam locator 340 by, for example, translating downlink beam locator 340 into a unique downlink beam identifier.
- Cell relay satellite 150 a then relays each cell 300 in order of arrival to the identified output port, which in turn transmits each cell 300 on a downlink beam corresponding to downlink beam locator 340 .
- Each node for example, node 100 b and node 100 c , in the footprint of the downlink bean of cell relay satellite 150 a receives each cell 300 .
- receiver 260 in node 100 b receives each cell 300 via antenna 270 , and stores each cell in memory 210 of node 100 b .
- Receiver 260 then generates an interrupt signal in processor 200 , and provides Packet Reassembler 214 the address of each cell 300 in memory 210 , as each cell 300 arrives at node 100 b .
- FIG. 7 illustrates a flow chart of the steps that Packet Reassembler 214 in node 100 b , performs to re-assemble packet 400 from one or more cells received by node 100 b in accordance with an implementation of the invention
- Packet Reassembler 214 receives from receiver 260 address of cell 300 in memory 210 (step 700 ). From node identifier 350 in cell header 310 , Packet Reassembler 214 identifies the address of the node that transmitted cell 300 , for example, node 110 a (step 705 ). Packet Reassembler 214 then determines whether a partially assembled packet from node 100 a already exists in memory 210 (step 710 ).
- Packet Reassembler 214 determines that a partially assembled packet from node 100 a does not exist in memory 210 (step 715 ). Packet Reassembler 214 starts a new partially assembled packet in memory 210 (step 720 ). Specifically, Packet Reassembler 214 strips cell header 310 from cell payload 320 , which includes a segment of packet 400 , and stores the segment in memory 210 . Packet Reassembler 214 then waits to receive the address of the next newly arriving cell in memory 210 (step 700 ).
- Packet Reassembler 214 determines that a partially assembled packet from node 100 a already exists in memory 210 (step 725 ). Packet Reassembler 214 strips cell header 310 from cell payload 320 , and prepends the segment of packet 400 in cell payload 320 to the partially assembled packet stored in memory 210 (step 730 ).
- Packet Reassembler 214 determines whether cell payload 320 includes the last segment of packet 400 (step 735 ). Specifically, Packet Reassembler 214 may read, for example, the last bit of prefix 330 in cell header 310 to make this determination. If the last bit of prefix 330 is “0”, then Packet Reassembler 214 determines that cell payload 320 does not include the last segment of packet 400 (step 740 ). Packet Reassembler 214 then waits to receive the address of the next newly arriving cell in memory 210 (step 700 ). If the last bit of prefix 330 is “1,” then Packet Reassembler 214 determines that cell payload 320 includes the last segment of packet 400 and that packet 400 has been re-assembled in memory 210 (step 745 ).
- Packet Reassembler 214 then performs error checking on the re-assembled packet 400 (step 750 ). For example, Packet Reassembler 214 may use packet header checksum field in packet header 410 to perform the error checking step. In the implementation shown in FIG. 5, Packet Reassembler 214 may use the 4 bytes CRC field in trailer 520 to perform error checking on the appended and prepended packet 500 . In this implementation, upon successful completion of the error checking step, Packet Reassembler 214 strips header 510 , trailer 520 , and null padding 530 , if any, from the appended and prepended packet 500 to successfully re-assemble packet 400 .
- node 100 b may identify in packet header 410 the destination node address of packet 400 , for example IP address of node 100 g , and may route packet 400 through IP network 130 to node 100 g (step 755 ).
- Node 100 c performs the same steps as node 100 b to receive each cell 300 and to re-assemble packet 400 .
- node 100 c determines that it cannot route packet 400 to node 100 g , and thus, discards packet 400 .
Abstract
Description
- 1. Field of the Invention
- The present invention generally relates to cell relay satellite communication networks, and more particularly, to connectionless cell relay satellite networks.
- 2. Background of the Art
- With the deployment of connection-oriented cell relay networks such as Asynchronous Transfer Mode (ATM) networks, there is a growing need for integrating cell relay networks with the existing packet-based networks, for example, Internet Protocol (IP) networks. In a connection-oriented network, the network must establish a connection (called a virtual circuit) between two nodes in the network with a signaling protocol before any information transfer can take place between the two nodes. Once the network establishes the connection between the two nodes, the network can identify and route the cells transmitted by the two nodes through the network. As a result, the existing cell relay networks must establish a connection between a source node and a destination node in the cell relay networks in order to transport IP traffic over the cell relay networks.
- In general, satellite-based cell relay networks offer certain advantages over terrestrial cell relay networks. For example, a satellite-based cell relay network can provide rapid deployment of communication services over a wide geographical area, including remote, rural, urban, and inaccessible areas. Furthermore, satellite-based cell relay networks offer more flexibility in configuring a network and allocating capacity to different sites. Thus, there is a need for a cell relay satellite network that can support the traffic from the existing packet-based communication networks.
- Connection-oriented cell relay satellite networks, however, have two significant disadvantages when transporting packet-based traffic from the existing networks. First, the connection-oriented cell relay satellite network must establish a connection between a source node and a destination node before any information transfer can take place between the source node and the destination node, and as a result, the information transfer will experience an initial delay due to the connection setup phase. Second, the satellite network must assign a unique identifier to each connection and manage the assignment of the identifiers so that the network can efficiently reuse each identifier when establishing a new connection.
- Each of these two disadvantages are particularly magnified in a cell relay satellite network. A satellite footprint typically covers a wide geographical area, which may include large number of users, and thus, requires a large number of corresponding connection identifiers to support the users. Furthermore, each communication with, for example, a geosynchronous satellite typically experiences a 500 milliseconds round trip delay, which increases the delay due to the connection setup phase.
- Thus, it is desirable to have a method and system for communicating packet-based traffic over a cell relay satellite network without establishing a connection in the cell relay satellite network, and thus, eliminating the above-mentioned disadvantages.
- The present invention comprises a method and system for communicating a packet over a cell relay satellite network, without establishing a connection in the cell relay satellite network, by dividing the packet into a number of segments at a source node in the communications network, generating for each segment a fixed size cell that includes a cell header and a payload, with a prefix, a downlink beam locator, and a source node identifier inside each cell header, inserting each of the segments into the payload of each of the generated cells, respectively, and transmitting the cells to the cell relay satellite. The cell relay satellite receives each transmitted cell from the source node, and broadcasts each cell on a downlink beam corresponding to the downlink beam locator in each cell header.
- A destination node in the cell relay satellite network receives each broadcasted cell on the downlink beam, and re-assembles the packet from the segments inside the payloads of the received cells. Specifically, the destination node re-assembles the packet by identifying the cells corresponding to the packet, and appending the segments inside the payloads of the identified cells together in the order of receipt of the identified cells. Finally, the destination node may identify a destination address in the packet, and may route the packet to the identified destination address, which may reside in another communications network.
- Methods and systems consistent with the present invention have two notable advantages over the existing cell relay satellite networks: First, a cell relay satellite network consistent with the present invention does not need to establish a connection in the network, and thus, eliminating the initial connection setup delay in the existing cell relay networks. Second, a cell relay satellite network consistent with the present invention does not need to expend valuable network processing resources for managing the assignment of unique identifiers to connections in the network.
- This summary and the following description of the invention should not restrict the scope of the claimed invention. Both provide examples and explanations to enable others to practice the invention. The accompanying drawings, which form part of the description of the invention, show several embodiments of the invention, and together with the description, explain the principles of the invention.
- In the Figures:
- FIG. 1 illustrates a cell relay satellite network in which systems and methods consistent with the invention may be implemented;
- FIG. 2 illustrates a block diagram of a node in a cell relay satellite network in which systems and methods consistent with the invention may be implemented;
- FIG. 3 illustrates a block diagram of a cell in a cell relay satellite network when using systems and methods consistent with the invention;
- FIG. 4 illustrates a block diagram of a packet, which a node in a cell relay satellite network may communicate through the cell relay satellite network when using systems and methods consistent with the invention;
- FIG. 5 illustrates a block diagram of a packet, which a node in a cell relay satellite network may communicate through the cell relay satellite network when using systems and methods consistent with the invention;
- FIG. 6 illustrates a flow chart of the steps that a node performs to segment a packet into one or more cells for transmission in a cell relay satellite network when using systems and methods consistent with the invention; and
- FIG. 7 illustrates a flow chart of the steps that a destination node performs to reassemble a packet from one or more cells in a cell relay satellite network when using systems and methods consistent with the invention.
- The following description refers to the accompanying drawings. Where appropriate, the same reference numbers in different drawings refer to the same or similar elements.
- Methods and systems consistent with the present invention communicate a packet over a cell relay satellite network, without establishing a connection in the cell relay satellite network, by dividing the packet into one or more segments at a source node in the cell relay satellite network. For each segment, the source node generates a fixed size cell that includes a cell header and a payload. The source node includes in each cell header a prefix, a downlink beam locator, and a source node identifier, and inserts the segments into the payloads of the generated cells respectively. The source node then transmits the cells on an uplink beam to the cell relay satellite.
- The cell relay satellite receives each transmitted cell on the uplink beam from the source node. The cell relay satellite reads the downlink identifier in each cell header, and identifies a downlink beam corresponding to the downlink beam locator. The cell relay satellite then broadcasts each cell on the identified downlink beam to a destination node within the footprint of the beam in the cell relay satellite network.
- The destination node receives each broadcasted cell on the downlink beam, and re-assembles the packet from the received cells. Specifically, the destination node identifies the cells corresponding to the packet, and appends the identified segments inside the payloads of the identified cells together in the order of receipt of the identified cells. Finally, the destination node may identify a destination address in the packet, and may route the packet to the identified destination address, which may reside in another communications network.
- FIG. 1 illustrates a cell
relay satellite network 110 in which systems and methods consistent with the invention may be implemented. Cellrelay satellite network 110 comprisescell relay satellites 150 a through 150 d, andsatellite node terminals 100 a through 100 f.Cell relay satellite 150 a communicates withcell relay satellites beams Cell relay satellite 150 b communicates withcell relay satellite 150 c viabeam 155 b, andcell relay satellite 150 c communicates withcell relay satellite 150 d viabeam 155 c. -
Nodes 100 a through 100 f may include earth station terminals, for example, very small aperture terminals (VSAT), which communicate with each other throughcell relay satellites 150 a through 150 d. Specifically,nodes 100 a through 100 c are in the beam footprints ofcell relay satellite 150 a,node 100 d is in the beam footprint ofcell relay satellite 150 b, andnodes satellite 150 d. Nodes 100 a through 100 f communicate with their respectivecell relay satellites 150 a through 150 d via uplink and downlink beams. -
Nodes network 120, andnodes IP network 130. Nodes 100 g through 100 j, which are not in the beam footprint ofcell relay satellites 150 a through 150 d, also interface withIP network 130. Similarly,nodes 100 k through 100 m, which are not in the beam footprint ofcell relay satellites 150 a through 150 d, interface withIP network 120.Nodes 100 g through 100 m may include, for example, desktop computers, servers, telephone sets, facsimile machines, and video apparatus. -
Nodes 100 g through 100 j may communicate withnodes 100 k through 100 m via satellitecell relay network 110. For example,node 100 k may generate information, for example, voice, data, and/or video, in form of packets, whichnode 100 k transmits throughIP network 120 to a node that interfacesIP network 120, for example,node 100 a.Node 100 a then segments the packets into one or more segments, insert each segment into payload of a cell, and transmits the cells throughcell relay satellite 150 a tonode 100 b.Node 100 b then reassembles the packets from the cells and routes the assembled packets throughIP network 130 to a destination node, for example,node 100 j, whose address is specified in the packets. - FIG. 2 illustrates a block diagram of a node, for example,
node 100 a, in cellrelay satellite network 110.Node 100 a comprises aprocessor 200, amemory 210, asecondary storage 220, anetwork interface card 230, atransmitter 250, areceiver 260, anantenna 270, andlinks bus 240. -
Memory 210 includesPacket Converter 212,Packet Reassembler 214, andIP Protocol Module 216, all of which include data and/or instructions thatprocessor 200 executes.Packet Converter 212 generally segments a packet into one or more segments and inserts each segment into a cell.Packet Reassembler 214 generally reassembles a packet from one or more cells, each including a segment of the packet.IP Protocol Module 216 generally includes Internet Protocol (IP), for example, IP version 4, for communicating packets throughIP network 120. Specifically,IP Protocol Module 216 drives Network interface card (NIC) 230 for transmitting and receiving packets throughIP network 120.NIC 230 may include hardware and/or firmware for transmitting and receiving packets fromIP network 120. -
Secondary storage 220 comprises computer readable medium such as a disk drive and a tape drive. From the tape drive, software and data may be loaded onto the disk drive, which can then be copied intomemory 210. Similarly, software and data inmemory 210 may be copied onto the disk drive, which can then be loaded onto the tape drive. -
Transmitter 250 connects toantenna 270 vialink 255.Transmitter 250 may include a codec and a frequency up converter for transmitting cells viaantenna 270 tocell relay satellite 150 a.Receiver 260 connects toantenna 270 vialink 265.Receiver 260 may include a codec and a frequency down converter for receiving cells viaantenna 270 fromcell relay satellite 150 a. - FIG. 3 is a block diagram of a cell for use in cell
relay satellite network 110 in accordance with an implementation of the invention. As shown,cell 300 includes acell header 310 portion and apayload 320 portion.Cell header 310 has a length of H bytes, andpayload 320 has a length of P bytes.Cell 300 may be of any fixed length, for example, 53 bytes, wherecell header 310 may have a length of, for example, 5 bytes andpayload 320 may have a length of, for example, 48 bytes. Alternatively,cell 300 may be of any other fixed length, with any combination ofcell header 310 length andpayload 320 length, as a particular length for each is not essential to the practice of the present invention. - Specifically,
cell header 310 includesprefix 330,downlink beam locator 340,source node identifier 350, andsuffix 360.Prefix 330 has a fixed length of K bits;downlink beam locator 340 has a fixed length of M bits;node identifier 350 has a fixed length of N bits; andsuffix 360 has a fixed length of J bits. In one example, prefix 330 may have a length of 6 bits;downlink beam locator 340 may have a length of 9 bits;node identifier 350 may have a length of 20 bits; and suffix 360 may have a length of 5 bits. Alternatively,prefix 330,downlink beam locator 340,node identifier 350, and suffix 360 may be of any combination of lengths, as a particular length for each is not essential to the practice of the present invention. - The first 2 bits of
prefix 330 may identify the particular protocol, for example, IP version 4, for handling a re-assembled packet. The next 3 bits ofprefix 330 may identify the handling instructions within the particular protocol, for example, the relative priority level within IP version 4. The last bit ofprefix 330 may, identify the type ofpayload 320 incell 300, for example, whetherpayload 320 includes the last segment of the packet or other segments of the packet. For example, ifpayload 320 includes the last segment of the packet, the last bit ofprefix 330 is set to “1.” Otherwise, the last bit ofprefix 330 is set to “0.” -
Downlink beam locator 340 may identify a particular downlink beam in a cell relay satellite, for example,cell relay satellite 150 a, on whichcell 300 may be transmitted to a destination node. Alternatively, the first 2 bits ofdownlink beam locator 340 may identifycell relay satellite 150 a, and the remaining bits indownlink beam locator 340 may identify a particular downlink beam incell relay satellite 150 a on whichcell 300 may be transmitted. Alternatively,downlink beam locator 340 may include a key or pointer, whichcell relay satellite 150 a must translate in order to identify the corresponding downlink beam. -
Node identifier 350 may identify a source node, for example,node 100 a that initiated transmission ofcell 300. Suffix 360 may include a cell header error check (HEC) for error checkingcell header 310. - FIG. 4 illustrates a block diagram of
packet 400, whichnode 100 a in cellrelay satellite network 110 communicates in accordance with an implementation of the invention.Packet 400 includes apacket header 410 portion anddata 420 portion.Packet header 410 may have a variable length of I bytes.Data 420 may have a variable length of T bytes. As shown,packet header 410 may include, for example, a version, header length, type of service, total packet length, packet identification, flags, fragment offset, time to live, protocol identifier, packet header checksum, source node address, destination node address, and other IP protocol options. Alternatively,packet header 410 may include any other combination of fields, as the particular format and types of information inpacket header 410 are not essential to the practice of the present invention. - A node in cell
relay satellite network 110, forexample node 100 a, may receive from another node, for example node, 100 k,packet 400 withpacket header 410 specifying destination node address of, for example,node 100 g, which interfacesIP network 130. Specifically,NIC 230 receivespacket 400 fromIP network 120, and storespacket 400 inmemory 210 viabus 240.NIC 230 then generates an interrupt signal inprocessor 200, and provides the address ofpacket 400 stored inmemory 210 toPacket Converter 212. - FIG. 6 illustrates a flow chart of the steps that
Packet Converter 212 innode 100 a performs tosegment packet 400 into one or more cells for transmission in cellrelay satellite network 110 in accordance with an implementation of the invention.Packet Converter 212 receives fromNIC 230 the memory address ofpacket 400 in memory 210 (step 600).Packet Converter 212 reads the destination node address in packet header 410 (step 610).Node 100 a then identifies a downlink beam in cellrelay satellite network 110 for routingpacket 400 tonode 100 g (step 620). Specifically,Packet Converter 212 identifies the downlink beam locator by referencing, for example, a stored routing table whose entry maps a destination node address, for example,node 100 g, to a particular downlink beam locator in cellrelay satellite network 110. The stored routing table may be generated by, for example,IP Protocol Module 216. -
Packet Converter 212 thensegments packet 400 into fixed size segments of, for example, 48 bytes (step 630). Alternatively, as shown in FIG. 5,Packet Converter 212 may prependheader 510 portion, and appendnull padding 530 portion andtrailer 520 portion to packet before segmentingpacket 400.Header 510 may have a length of R bytes.Trailer 520 may have a length of L bytes. Furthermore,Packet Converter 212 may determine the length ofnull padding 530 to be such that the combined length ofpacket 400,header 530,trailer 420, andnull padding 530 becomes a multiple integer of the length ofpayload 320 incell 300. This combined length may be determined as follows: - combined length=P*{smallest integer greater than or equal to [(T+I+R+L)/P]},
- where, as described above, P is length of
payload 320, I is length ofpacket header 410, and T is length ofdata 420 portion ofpacket 400. From the computed combined length, thenull padding 530 length may be determined as follows: - null padding length=combined length−T−I−R−L.
- In this alternative configuration,
packet 400 may have a length of, for example, 500 bytes, andcell payload 320 may have a length of, for example, 48 bytes.Header 510 may have a length of 8 bytes, and may include, for example, the identifier “0xAA-AA-03-00-00-00-08-00,” disclosed in “Multiple-Protocol Encapsulation Over AAL5,” Internet Engineering Task Force, RFC 1483.Trailer 520 may also have a length of 8 bytes, whose first 2 bytes represent the length ofpacket 400, the second 4 bytes include a cyclical redundancy code (CRC) for error checking, and the last 2 bytes are null. Thus,Packet Converter 212 determines the combined length and length ofnull padding 530 as follows: - combined length=528 bytes=48 bytes*{smallest integer>=(500 bytes+8 bytes+8 bytes)/48 bytes},
- length of null padding=12 bytes=(528 bytes−500 bytes−8 bytes−8 bytes).
- Finally, after prepending
header 510, and appendingnull padding 530 andtrailer 520 topacket 400,Packet Converter 212, segments the appended andprepended packet 500 into fixed size segments of 48 bytes. -
Packet Converter 212 then createscell header 310 for each packet segment (step 640), and prependscell header 310 to each packet segment (step 650). Specifically, in thecell header 310 prepended to the each segment,Packet Converter 212 sets the first 2 bits ofprefix 330 to identify the particular protocol, for example, IP version 4, for handling the reassembled packet.Packet Converter 212 then sets the next 3 bits ofprefix 330 to identify the relative priority level within IP version 4. Finally,Packet Converter 212 sets the last bit ofprefix 330 to identify the type ofpayload 320 incell 300, for example, whetherpayload 320 includes the last segment ofpacket 400 or other segments of the packet. Ifcell header 310 is prepended to the last segment ofpacket 400,Packet Converter 212 sets the last bit ofprefix 330 to “1.” Otherwise,Packet Converter 212 sets the last bit ofprefix 330 to “0.” -
Packet Converter 212 setsdownlink beam locator 340 in eachcell header 310 to the downlink beam identifier thatPacket Converter 212 identified instep 620. Furthermore,Packet Converter 212 setsnode identifier 350 in eachcell header 310 to the address ofnode 100 a.Packet Converter 212 calculates a header error check (HEC) and includes the HEC insuffix 360 of eachcell header 310. Finally,Packet Converter 212 generates an interrupt signal inprocessor 200, and provides the address of each completed cell inmemory 210 totransmitter 250.Transmitter 250 then transmits each cell in order starting with the cell that includes the first packet segment and ending with the cell that includes the last packet segment throughantenna 270 and via an uplink beam tocell relay satellite 150 a. -
Cell relay satellite 150 a receives eachcell 300 at an input port, which receives the uplink beam.Cell relay satellite 150 a then readsdownlink beam locator 340 in eachcell header 310, and identifies an output port corresponding to downlinkbeam locator 340 by, for example, translatingdownlink beam locator 340 into a unique downlink beam identifier.Cell relay satellite 150 a then relays eachcell 300 in order of arrival to the identified output port, which in turn transmits eachcell 300 on a downlink beam corresponding to downlinkbeam locator 340. - Each node, for example,
node 100 b andnode 100 c, in the footprint of the downlink bean ofcell relay satellite 150 a receives eachcell 300. Specifically,receiver 260 innode 100b receives eachcell 300 viaantenna 270, and stores each cell inmemory 210 ofnode 100 b.Receiver 260 then generates an interrupt signal inprocessor 200, and providesPacket Reassembler 214 the address of eachcell 300 inmemory 210, as eachcell 300 arrives atnode 100 b. - FIG. 7 illustrates a flow chart of the steps that
Packet Reassembler 214 innode 100 b, performs to re-assemblepacket 400 from one or more cells received bynode 100 b in accordance with an implementation of theinvention Packet Reassembler 214 receives fromreceiver 260 address ofcell 300 in memory 210 (step 700). Fromnode identifier 350 incell header 310,Packet Reassembler 214 identifies the address of the node that transmittedcell 300, for example, node 110 a (step 705).Packet Reassembler 214 then determines whether a partially assembled packet fromnode 100 a already exists in memory 210 (step 710). - If
Packet Reassembler 214 determines that a partially assembled packet fromnode 100 a does not exist in memory 210 (step 715),Packet Reassembler 214 starts a new partially assembled packet in memory 210 (step 720). Specifically,Packet Reassembler 214strips cell header 310 fromcell payload 320, which includes a segment ofpacket 400, and stores the segment inmemory 210.Packet Reassembler 214 then waits to receive the address of the next newly arriving cell in memory 210 (step 700). - If
Packet Reassembler 214 determines that a partially assembled packet fromnode 100 a already exists in memory 210 (step 725),Packet Reassembler 214strips cell header 310 fromcell payload 320, and prepends the segment ofpacket 400 incell payload 320 to the partially assembled packet stored in memory 210 (step 730). -
Packet Reassembler 214 then determines whethercell payload 320 includes the last segment of packet 400 (step 735). Specifically,Packet Reassembler 214 may read, for example, the last bit ofprefix 330 incell header 310 to make this determination. If the last bit ofprefix 330 is “0”, thenPacket Reassembler 214 determines thatcell payload 320 does not include the last segment of packet 400 (step 740).Packet Reassembler 214 then waits to receive the address of the next newly arriving cell in memory 210 (step 700). If the last bit ofprefix 330 is “1,” thenPacket Reassembler 214 determines thatcell payload 320 includes the last segment ofpacket 400 and thatpacket 400 has been re-assembled in memory 210 (step 745). -
Packet Reassembler 214 then performs error checking on the re-assembled packet 400 (step 750). For example,Packet Reassembler 214 may use packet header checksum field inpacket header 410 to perform the error checking step. In the implementation shown in FIG. 5,Packet Reassembler 214 may use the 4 bytes CRC field intrailer 520 to perform error checking on the appended andprepended packet 500. In this implementation, upon successful completion of the error checking step,Packet Reassembler 214strips header 510,trailer 520, andnull padding 530, if any, from the appended andprepended packet 500 to successfully re-assemblepacket 400. - Once
node 100 b re-assemblespacket 400,node 100 b may identify inpacket header 410 the destination node address ofpacket 400, for example IP address ofnode 100 g, and may routepacket 400 throughIP network 130 tonode 100 g (step 755).Node 100 c performs the same steps asnode 100 b to receive eachcell 300 and to re-assemblepacket 400. However, whennode 100 c identifies inpacket header 410 the destination node address ofpacket 400,node 100 c determines that it cannot routepacket 400 tonode 100 g, and thus, discardspacket 400. - It will be understood by those skilled in the art that various changes and modifications may be made to the disclosed implementations, and equivalents may be substituted for elements thereof without departing from the true scope of the invention. In addition, many modifications may be made to adapt a particular element, technique or implementation to the teachings of the present invention without departing from the central scope of the invention. Therefore, it is intended that this invention not be limited to the particular implementations and methods disclosed herein, but that the invention include all implementations falling within the scope of the appended claims.
Claims (13)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US09/938,923 US20020122420A1 (en) | 1998-06-17 | 2001-08-24 | Method and system for connectionless communication in a cell relay satellite network |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US09/098,622 US6310893B1 (en) | 1998-06-17 | 1998-06-17 | Method and system for connectionless communication in a cell relay satellite network |
US09/938,923 US20020122420A1 (en) | 1998-06-17 | 2001-08-24 | Method and system for connectionless communication in a cell relay satellite network |
Related Parent Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US09/098,622 Continuation US6310893B1 (en) | 1998-06-17 | 1998-06-17 | Method and system for connectionless communication in a cell relay satellite network |
Publications (1)
Publication Number | Publication Date |
---|---|
US20020122420A1 true US20020122420A1 (en) | 2002-09-05 |
Family
ID=22270163
Family Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US09/098,622 Expired - Fee Related US6310893B1 (en) | 1998-06-17 | 1998-06-17 | Method and system for connectionless communication in a cell relay satellite network |
US09/938,923 Abandoned US20020122420A1 (en) | 1998-06-17 | 2001-08-24 | Method and system for connectionless communication in a cell relay satellite network |
Family Applications Before (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US09/098,622 Expired - Fee Related US6310893B1 (en) | 1998-06-17 | 1998-06-17 | Method and system for connectionless communication in a cell relay satellite network |
Country Status (7)
Country | Link |
---|---|
US (2) | US6310893B1 (en) |
EP (1) | EP1088413A4 (en) |
JP (1) | JP2002518933A (en) |
AU (1) | AU4823199A (en) |
CA (1) | CA2335021A1 (en) |
IL (1) | IL139486A (en) |
WO (1) | WO1999066662A1 (en) |
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20020154633A1 (en) * | 2000-11-22 | 2002-10-24 | Yeshik Shin | Communications architecture for storage-based devices |
US6801941B1 (en) * | 1999-08-12 | 2004-10-05 | Sarnoff Corporation | Dynamic wireless internet address assignment scheme with authorization |
US20050083852A1 (en) * | 2001-01-19 | 2005-04-21 | Ari Alastalo | Apparatus, and associated method, for utilizing antenna information determinative of antenna operation in a wireless mesh network |
US20070239987A1 (en) * | 2006-03-31 | 2007-10-11 | Amazon Technologies, Inc. | Managing communications between computing nodes |
US20080219435A1 (en) * | 2007-03-07 | 2008-09-11 | Fujitsu Limited | Information transmitting apparatus, information transmitting method, and computer product |
US20200052877A1 (en) * | 2015-06-11 | 2020-02-13 | Avago Technologies International Sales Pte. Limited | Synchronization and training stage operation |
US10592262B1 (en) | 2011-06-27 | 2020-03-17 | Amazon Technologies, Inc. | Managing shared computing environments |
Families Citing this family (34)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6700958B2 (en) * | 1995-04-10 | 2004-03-02 | Starguide Digital Networks, Inc. | Method and apparatus for transmitting coded audio signals through a transmission channel with limited bandwidth |
BR9610270A (en) * | 1995-08-16 | 1999-07-06 | Starguide Digital Networks Inc | Dynamic bandwidth allocation for transmission of audio signals and a video signal |
EP0847638A4 (en) * | 1995-09-01 | 2002-08-21 | Starguide Digital Networks Inc | Audio file distribution and production system |
US6791947B2 (en) | 1996-12-16 | 2004-09-14 | Juniper Networks | In-line packet processing |
US6442147B1 (en) * | 1997-04-18 | 2002-08-27 | Nortel Networks Limited | Connectionless communications network |
WO1998048593A1 (en) * | 1997-04-18 | 1998-10-29 | Northern Telecom Limited | Connectionless communications network |
GB2324435A (en) * | 1997-04-18 | 1998-10-21 | Northern Telecom Ltd | Connectionless communication network with changing topology |
US7194757B1 (en) | 1998-03-06 | 2007-03-20 | Starguide Digital Network, Inc. | Method and apparatus for push and pull distribution of multimedia |
US6160797A (en) | 1998-04-03 | 2000-12-12 | Starguide Digital Networks, Inc. | Satellite receiver/router, system, and method of use |
US8284774B2 (en) | 1998-04-03 | 2012-10-09 | Megawave Audio Llc | Ethernet digital storage (EDS) card and satellite transmission system |
US6430167B1 (en) * | 1998-08-03 | 2002-08-06 | Trw Inc. | Method for transferring data over a satellite network by using unique beam identifiers to route the data |
US6493342B1 (en) * | 1998-09-11 | 2002-12-10 | Teledesic Llc | Method of data transmission in a data communication network |
EP1014641A1 (en) * | 1998-12-22 | 2000-06-28 | Telefonaktiebolaget Lm Ericsson | Method and system for reducing the processing time of data in communication networks |
US6625145B1 (en) * | 1998-12-30 | 2003-09-23 | Telefonaktiebolaget Lm Ericsson (Publ) | Use of lower IP-address bits |
US6404749B1 (en) * | 1999-03-08 | 2002-06-11 | Trw Inc. | Method for providing connectionless data services over a connection-oriented satellite network |
US6785239B1 (en) * | 1999-06-01 | 2004-08-31 | Cisco Technology, Inc. | Reducing delays in a communication network using a re-fragmentation pipeline |
US6604146B1 (en) * | 1999-06-15 | 2003-08-05 | Viasat, Inc. | Efficient internet service implementation for mesh satellite networks using centralized router server for distribution of destination tables |
US6934250B1 (en) | 1999-10-14 | 2005-08-23 | Nokia, Inc. | Method and apparatus for an output packet organizer |
US6882642B1 (en) | 1999-10-14 | 2005-04-19 | Nokia, Inc. | Method and apparatus for input rate regulation associated with a packet processing pipeline |
US6757249B1 (en) | 1999-10-14 | 2004-06-29 | Nokia Inc. | Method and apparatus for output rate regulation and control associated with a packet pipeline |
US6804258B1 (en) * | 1999-12-07 | 2004-10-12 | Sun Microsystems, Inc. | Method and apparatus for alleviating cell packing problems in bundled link systems |
US6704794B1 (en) * | 2000-03-03 | 2004-03-09 | Nokia Intelligent Edge Routers Inc. | Cell reassembly for packet based networks |
US7113493B1 (en) * | 2000-06-02 | 2006-09-26 | General Electric Company | Active networking in communication satellites |
WO2002069073A2 (en) * | 2000-11-13 | 2002-09-06 | Starguide Digital Networks, Inc. | Ethernet digital storage (eds) card and satellite transmission system including faxing capability |
FR2817057B1 (en) * | 2000-11-20 | 2003-02-07 | Cit Alcatel | METHOD OF ADDRESSING IN A SATELLITE ACCESS OR INFRASTRUCTURE NETWORK |
US7095744B2 (en) * | 2000-11-22 | 2006-08-22 | Dune Networks | Method and system for switching variable sized packets |
FR2836766B1 (en) * | 2002-03-04 | 2006-03-24 | Cit Alcatel | RESOURCE MANAGER DEVICE FOR A SATELLITE TELECOMMUNICATION SYSTEM |
US20040179493A1 (en) * | 2003-03-14 | 2004-09-16 | Khan Farooq Ullah | Methods of transmitting channel quality information and power allocation in wireless communication systems |
ES2285104T3 (en) * | 2003-03-18 | 2007-11-16 | Nokia Corporation | METHOD, SYSTEM AND NETWORK ENTITY FOR THE TRANSMISSION AND RECEIPT OF DATA WITH HEAD PROTECTION. |
FR2854522B1 (en) * | 2003-04-30 | 2005-09-30 | Cit Alcatel | DEVICE FOR PROCESSING DATA PACKET INTETS FOR TWO LEVEL SWITCHING VIA A LOGIC BUS WITHIN A SATELLITE COMMUNICATIONS NETWORK. |
US7673219B2 (en) * | 2006-03-16 | 2010-03-02 | Mitsubishi Electric Research Laboratories, Inc. | Cooperative relay networks using rateless codes |
US8325623B1 (en) | 2010-02-16 | 2012-12-04 | Google Inc. | System and method for reducing latency during data transmissions over a network |
JP5600215B2 (en) * | 2010-10-04 | 2014-10-01 | テルコーディア テクノロジーズ インコーポレイテッド | Method and system for determining a route in an LEO satellite network using bandwidth and priority awareness and adaptive routing |
US20220201587A1 (en) * | 2020-12-19 | 2022-06-23 | Meteorcomm, Llc | End of Train to Head of Train Communication Over a Train Control Network |
Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5065398A (en) * | 1988-05-16 | 1991-11-12 | Hitachi, Ltd. | TDMA satellite communication method and system |
US5396643A (en) * | 1992-08-24 | 1995-03-07 | Motorola, Inc. | Geographic-area selective low-earth satellite-based paging broadcast system and method |
US5432777A (en) * | 1991-08-21 | 1995-07-11 | International Business Machines Corp. | Connectionless ATM data services |
US5563879A (en) * | 1994-09-06 | 1996-10-08 | Motorola, Inc. | Method of reconstructing and delivering segmented messages |
US5600629A (en) * | 1994-07-25 | 1997-02-04 | Motorola, Inc. | Inter-satellite method for routing packets |
US5852721A (en) * | 1994-06-08 | 1998-12-22 | Hughes Electronics Corporation | Method and apparatus for selectively retrieving information from a source computer using a terrestrial or satellite interface |
US5909439A (en) * | 1995-05-30 | 1999-06-01 | Mitsubishi Denki Kabushiki Kaisha | Satellite communications system |
US6172972B1 (en) * | 1996-05-28 | 2001-01-09 | Microsoft Corporation | Multi-packet transport structure and method for sending network data over satellite network |
Family Cites Families (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2682243A1 (en) * | 1991-10-04 | 1993-04-09 | France Telecom | METHOD OF ALLOCATING RESOURCES BY ANTICIPATED RESERVATION IN A SERVICE - INTEGRATION SATELLITE NETWORK. |
US5740164A (en) * | 1993-02-09 | 1998-04-14 | Teledesic Corporation | Traffic routing for satellite communication system |
CA2202116C (en) * | 1996-07-18 | 2000-08-01 | Liang Hsu | Packetized cdma/tdm satellite communication system |
-
1998
- 1998-06-17 US US09/098,622 patent/US6310893B1/en not_active Expired - Fee Related
-
1999
- 1999-06-15 CA CA002335021A patent/CA2335021A1/en not_active Abandoned
- 1999-06-15 EP EP99931801A patent/EP1088413A4/en not_active Withdrawn
- 1999-06-15 WO PCT/US1999/013502 patent/WO1999066662A1/en not_active Application Discontinuation
- 1999-06-15 AU AU48231/99A patent/AU4823199A/en not_active Abandoned
- 1999-06-15 JP JP2000555380A patent/JP2002518933A/en not_active Withdrawn
- 1999-06-15 IL IL13948698A patent/IL139486A/en not_active IP Right Cessation
-
2001
- 2001-08-24 US US09/938,923 patent/US20020122420A1/en not_active Abandoned
Patent Citations (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5065398A (en) * | 1988-05-16 | 1991-11-12 | Hitachi, Ltd. | TDMA satellite communication method and system |
US5432777A (en) * | 1991-08-21 | 1995-07-11 | International Business Machines Corp. | Connectionless ATM data services |
US5517497A (en) * | 1991-08-21 | 1996-05-14 | International Business Machines Corporation | Connectionless ATM data services |
US5396643A (en) * | 1992-08-24 | 1995-03-07 | Motorola, Inc. | Geographic-area selective low-earth satellite-based paging broadcast system and method |
US5852721A (en) * | 1994-06-08 | 1998-12-22 | Hughes Electronics Corporation | Method and apparatus for selectively retrieving information from a source computer using a terrestrial or satellite interface |
US5600629A (en) * | 1994-07-25 | 1997-02-04 | Motorola, Inc. | Inter-satellite method for routing packets |
US5563879A (en) * | 1994-09-06 | 1996-10-08 | Motorola, Inc. | Method of reconstructing and delivering segmented messages |
US5909439A (en) * | 1995-05-30 | 1999-06-01 | Mitsubishi Denki Kabushiki Kaisha | Satellite communications system |
US6172972B1 (en) * | 1996-05-28 | 2001-01-09 | Microsoft Corporation | Multi-packet transport structure and method for sending network data over satellite network |
Cited By (24)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6801941B1 (en) * | 1999-08-12 | 2004-10-05 | Sarnoff Corporation | Dynamic wireless internet address assignment scheme with authorization |
US20020154633A1 (en) * | 2000-11-22 | 2002-10-24 | Yeshik Shin | Communications architecture for storage-based devices |
US20040004975A1 (en) * | 2000-11-22 | 2004-01-08 | Yeshik Shin | Method and system for nesting of communications packets |
US7154905B2 (en) | 2000-11-22 | 2006-12-26 | Silicon Image | Method and system for nesting of communications packets |
US20050083852A1 (en) * | 2001-01-19 | 2005-04-21 | Ari Alastalo | Apparatus, and associated method, for utilizing antenna information determinative of antenna operation in a wireless mesh network |
US20100318645A1 (en) * | 2006-03-31 | 2010-12-16 | Amazon Technologies, Inc. | Managing communications between computing nodes |
US9426181B2 (en) | 2006-03-31 | 2016-08-23 | Amazon Technologies, Inc. | Managing communications between computing nodes |
US7801128B2 (en) * | 2006-03-31 | 2010-09-21 | Amazon Technologies, Inc. | Managing communications between computing nodes |
US10764331B2 (en) | 2006-03-31 | 2020-09-01 | Amazon Technologies, Inc. | Network-accessible service for managing communications for computing node groups using rules |
US8509231B2 (en) * | 2006-03-31 | 2013-08-13 | Amazon Technologies, Inc. | Managing communications between computing nodes |
US11539753B2 (en) | 2006-03-31 | 2022-12-27 | Amazon Technologies, Inc. | Network-accessible service for executing virtual machines using client-provided virtual machine images |
US9253211B2 (en) | 2006-03-31 | 2016-02-02 | Amazon Technologies, Inc. | Managing communications between computing nodes |
US20070239987A1 (en) * | 2006-03-31 | 2007-10-11 | Amazon Technologies, Inc. | Managing communications between computing nodes |
US9621593B2 (en) | 2006-03-31 | 2017-04-11 | Amazon Technologies, Inc. | Managing execution of programs by multiple computing systems |
US9794294B2 (en) | 2006-03-31 | 2017-10-17 | Amazon Technologies, Inc. | Managing communications between computing nodes |
US10348770B2 (en) | 2006-03-31 | 2019-07-09 | Amazon Technologies, Inc. | Managing execution of programs by multiple computing systems |
US10367850B2 (en) | 2006-03-31 | 2019-07-30 | Amazon Technologies, Inc. | Managing communications between computing nodes |
US11451589B2 (en) | 2006-03-31 | 2022-09-20 | Amazon Technologies, Inc. | Configurable application execution service for executing applications on virtual machines |
US10791149B2 (en) | 2006-03-31 | 2020-09-29 | Amazon Technologies, Inc. | Network-accessible service for executing virtual machines using client-provided virtual machine images |
US20080219435A1 (en) * | 2007-03-07 | 2008-09-11 | Fujitsu Limited | Information transmitting apparatus, information transmitting method, and computer product |
US8571206B2 (en) | 2007-03-07 | 2013-10-29 | Fujitsu Limited | Information transmitting apparatus, information transmitting method, and computer product |
US10592262B1 (en) | 2011-06-27 | 2020-03-17 | Amazon Technologies, Inc. | Managing shared computing environments |
US10756882B2 (en) * | 2015-06-11 | 2020-08-25 | Avago Technologies International Sales Pte. Limited | Transition timing and training stage operation |
US20200052877A1 (en) * | 2015-06-11 | 2020-02-13 | Avago Technologies International Sales Pte. Limited | Synchronization and training stage operation |
Also Published As
Publication number | Publication date |
---|---|
IL139486A0 (en) | 2001-11-25 |
JP2002518933A (en) | 2002-06-25 |
IL139486A (en) | 2005-06-19 |
EP1088413A4 (en) | 2004-06-09 |
WO1999066662A1 (en) | 1999-12-23 |
US6310893B1 (en) | 2001-10-30 |
AU4823199A (en) | 2000-01-05 |
EP1088413A1 (en) | 2001-04-04 |
CA2335021A1 (en) | 1999-12-23 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US6310893B1 (en) | Method and system for connectionless communication in a cell relay satellite network | |
US8509139B2 (en) | Method of data transmission in a data communication network | |
US5596574A (en) | Method and apparatus for synchronizing data transmission with on-demand links of a network | |
US6094525A (en) | Network addressing arrangement for backward compatible routing of an expanded address space | |
US6985454B1 (en) | ISP system using non-geosynchronous orbit satellites | |
JP3575215B2 (en) | Packet communication method and communication terminal device | |
US5936967A (en) | Multi-channel broadband adaptation processing | |
US6295283B1 (en) | Method for providing connectionless data services over a connection-oriented satellite network by associating IP subnets with downlink beam identifiers | |
EP0455959A2 (en) | Method and system for routing packets in a packet communication network | |
US6674731B1 (en) | Transmission and reception of TCP/IP data over a wireless communication channel | |
EP0578041A2 (en) | Shortcut network layer routing for mobile hosts | |
US5892761A (en) | Method and apparatus for routing data in collaborative computing system | |
US6404749B1 (en) | Method for providing connectionless data services over a connection-oriented satellite network | |
WO2003036886A2 (en) | Method and system for transferring ip packets by aggregating multiple wireless communication channels for high data rate transfers | |
AU2002359302A1 (en) | Method and system for transferring IP packets by aggregating multiple wireless communication channels for high data rate transfers | |
US6226294B1 (en) | Multiplexing traffic into structure blocks in ATM cells | |
US6229823B1 (en) | System and method for the compression of proprietary encapsulations | |
US6665292B1 (en) | Transmission and reception of TCP/IP data over a wireless communication channel | |
US20030185215A1 (en) | Encapsulation method and apparatus for communicating fixed-length data packets through an intermediate network | |
US20130003651A1 (en) | Telecommunication system comprising a central ip router composed of a satellite and of a ground router | |
US6650636B1 (en) | Transmission and reception of TCP/IP data over a wireless communication channel | |
US6430167B1 (en) | Method for transferring data over a satellite network by using unique beam identifiers to route the data | |
US6738369B1 (en) | Method and arrangement for packet-switched data transmission | |
US20190190821A1 (en) | Method of optimizing spectral efficiency in an mpls interconnection context | |
JP2001016179A (en) | Transmission system taking requirements of various kinds of traffic to be carried into consideration and corresponding transmitter and receiver |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: BBNT SOLUTIONS LLC, MASSACHUSETTS Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:VERIZON CORPORATE SERVICES GROUP INC.;REEL/FRAME:014696/0756 Effective date: 20010421 |
|
AS | Assignment |
Owner name: FLEET NATIONAL BANK, AS AGENT, MASSACHUSETTS Free format text: PATENT AND TRADEMARKS SECURITY AGREEMENT;ASSIGNOR:BBNT SOLUTIONS LLC;REEL/FRAME:014709/0549 Effective date: 20040326 |
|
AS | Assignment |
Owner name: LEVEL 3 COMMUNICATIONS, INC., COLORADO Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:GENUITY, INC.;REEL/FRAME:016468/0239 Effective date: 20030204 |
|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |
|
AS | Assignment |
Owner name: BBNT SOLUTIONS LLC, MASSACHUSETTS Free format text: CORRECTIVE ASSIGNMENT TO CORRECT THE EXECUTION DATE PREVIOUSLY RECORDED AT REEL: 014696 FRAME: 0756. ASSIGNOR(S) HEREBY CONFIRMS THE ASSIGNMENT;ASSIGNOR:VERIZON CORPORATE SERVICES GROUP INC.;REEL/FRAME:016621/0835 Effective date: 20040421 Owner name: BBNT SOLUTIONS LLC, MASSACHUSETTS Free format text: CORRECTION OF EXCECUTION DATE OF ASSIGNMENT RECORD;ASSIGNOR:VERIZON CORPORATE SERVICES GROUP INC.;REEL/FRAME:016621/0835 Effective date: 20040421 |
|
AS | Assignment |
Owner name: VERIZON CORPORATE SERVICES GROUP INC., NEW JERSEY Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:BBN TECHNOLOGIES CORP.;REEL/FRAME:020112/0322 Effective date: 20071011 |
|
AS | Assignment |
Owner name: BBN TECHNOLOGIES CORP. (AS SUCCESSOR BY MERGER TO Free format text: RELEASE OF SECURITY INTEREST;ASSIGNOR:BANK OF AMERICA, N.A. (SUCCESSOR BY MERGER TO FLEET NATIONAL BANK);REEL/FRAME:023427/0436 Effective date: 20091026 |