WO1995025407A1 - Modem for packet and circuit switched communication - Google Patents

Modem for packet and circuit switched communication Download PDF

Info

Publication number
WO1995025407A1
WO1995025407A1 PCT/CA1995/000147 CA9500147W WO9525407A1 WO 1995025407 A1 WO1995025407 A1 WO 1995025407A1 CA 9500147 W CA9500147 W CA 9500147W WO 9525407 A1 WO9525407 A1 WO 9525407A1
Authority
WO
WIPO (PCT)
Prior art keywords
data
circuit switched
modem
over
packet
Prior art date
Application number
PCT/CA1995/000147
Other languages
French (fr)
Inventor
Norman Toms
Original Assignee
Sierra Wireless, Inc.
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Sierra Wireless, Inc. filed Critical Sierra Wireless, Inc.
Priority to AU19435/95A priority Critical patent/AU1943595A/en
Publication of WO1995025407A1 publication Critical patent/WO1995025407A1/en

Links

Classifications

    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W28/00Network traffic management; Network resource management
    • H04W28/02Traffic management, e.g. flow control or congestion control
    • H04W28/06Optimizing the usage of the radio link, e.g. header compression, information sizing, discarding information
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04MTELEPHONIC COMMUNICATION
    • H04M11/00Telephonic communication systems specially adapted for combination with other electrical systems
    • H04M11/06Simultaneous speech and data transmission, e.g. telegraphic transmission over the same conductors

Definitions

  • the present invention relates generally to the transmission of data over a wireless communications network and, more specifically, the present invention relates to an apparatus and method for controlling a modem that can be used with either a wireless packet data communication system or a wireless circuit switched communications system.
  • Packet radio communication systems are wireless communications systems for transmitting data or messages.
  • customers typically access the network through a radio frequency access device that connects the customer's data terminal to a packet switch.
  • CDPD cellular digital packet data
  • the CDPD network which is different from a conventional cellular telephone system based upon circuit switching, is expected to be a major advancement in wireless wide-area communications.
  • the proponents of the CDPD system envision the base equipment of a CDPD cell being co-located with the base station equipment of a conventional cellular telephone system.
  • AMPS Advanced Mobile Phone System
  • the original AMPS system is an analog system in which a plurality of base stations are connected to Mobile Telephone Switching Offices (MTSO) via land lines.
  • MTSO Mobile Telephone Switching Offices
  • PSTN public switched telephone network
  • the base stations transmit information using radio frequency carrier signals within a cell.
  • Mobile stations or cellular telephones operating within a particular base station cell are able to communicate with the base station, and the base station is able to connect the cellular telephone to the PSTN.
  • personal computers can be equipped with a specially adapted modem to transmit data over a cellular telephone system.
  • the personal computer is connected to the special purpose modem which, in turn, is coupled to a cellular telephone via a special connector.
  • a personal computer may also transmit data over a CDPD network using a modem specially adapted for that network.
  • the owner of a personal computer wishes to communicate over both networks, the owner must own both a special purpose modem for a cellular telephone system and a special purpose modem for a CDPD network.
  • the present invention provides a method and apparatus for transmitting data or information over either a wireless packet data system, such as a CDPD system, or transmitting data over a wireless circuit switched system, such as a conventional cellular telephone system. More particularly, the present invention provides a method and apparatus that allows data to be transferred over either a wireless packet data system, such as a CDPD system, or a wireless circuit switched system, such as a conventional cellular telephone system, using the same modem. In practice, systems according to the present invention address the combination of wireless packet circuit transmission or conventional cellular telephone transmission using the same radio.
  • the present invention includes a data source, such as a personal computer or telemetry device, to generate data.
  • the data from the data source is applied to a control means that controls a modem and a transceiver.
  • the modem is especially adapted to work with either a CDPD system or a conventional cellular telephone system.
  • the control means is able to select the most desirable system over which a link is to be established. For example, the control means could evaluate the quality of the connection on either system.
  • the control means then establishes a communication link on one system which is determined to be the best, according to some criteria which may be pre-set, selected dynamically by the user or otherwise established.
  • Figure 1A is a block diagram of the apparatus of the present invention
  • Figure IB is a block diagram of another embodiment of the present invention.
  • FIG. 1A is flowchart of the control means of Figure 1A.
  • a communications system includes a data source 10 which may be a personal computer, telemetry device or other means of generating data.
  • the output from data source 10 is applied to a control means which preferably includes a suitably programmed microprocessor.
  • the control means 11 controls a modem 12 and a transceiver 13.
  • the modem 12 is able to adaptively transmit data over a cellular telephone infrastructure in packet switched form or in circuit switched form. In the packet switched mode, data is transmitted from the data source 10 using the modem 12 which is designed to communicate via suitably modified base station receivers and transmitters as described in, for example, the CDPD specification.
  • the same radio is used to transmit data over a conventional cellular telephone system by controlling the radio to transmit and receive necessary signalling information needed to set up or to end circuit connection to a matching modem using, for example, the AMPS protocol in North America or other standards.
  • the control means 11 is used to determine whether the data to be transmitted from the data source 10 should be sent in packet switched form or circuit switched form based on criteria established either in manufacturing or dynamically by the user. One criterion would be the availability of the packet switched capability in the cellular infrastructure. In the dynamic case, the decision is made by the control means 11 attempting to initiate packet switched communications or by monitoring the radio channel to determine the presence or absence of control signals or traffic patterns associated with a packet communications channel. If the control means 11 determines there is no packet switched capability, then the communications would be initiated by circuit switched means over a conventional cellular telephone system.
  • the control means 11 also determines whether data can be transmitted in circuit switched form. In practice, the determination is based on the availability of circuit switched capability in the cellular infrastructure which is compatible with the control means. The decision is made by the control means 11 when it attempts to set up a circuit switched connection. In one scenario, the cellular infrastructure is unable to allocate circuit switched capacity (either due to the channels being busy or due to equipment failure or due to the fact that the base station with which the modem is communicating was designed to be "packet only"), then communications would be set up on the packet switched system. In another scenario, the cellular infrastructure does not support the protocol used in the modem (e.g. AMPS), and the modem is incapable of communicating using the protocol supported by the cellular infrastructure (e.g., a digital cellular protocol).
  • AMPS protocol used in the modem
  • the modem is incapable of communicating using the protocol supported by the cellular infrastructure (e.g., a digital cellular protocol).
  • ancillary software resident in the data source 10 or in the control means 11 determines which means of transmission is best for the data to be transmitted based on the criterion of cost.
  • the ancillary software or the control means may also determine which means of transmission is best for the data to be transmitted based on performance, such as response time, throughput or some other objective criteria.
  • the system according to the present invention preferably includes an error control strategy which is best for the circuit switched communication mode.
  • This error control strategy can be embedded in the ancillary software of the data source 10 or the control means 11.
  • the CDPD specification specifies one particular form of error control for packet data. There is economy to be gained by using the same error control for circuit switched data where appropriate fixed modems are available for communications.
  • the control means 11 preferably determines whether the fixed modem with which it is attempting to communicate over a circuit switched connection is able to interpret the CDPD error control scheme. If it is, then this would be the error control means of choice. Where it is not, an alternative scheme would be used.
  • an error control strategy which is best for the circuit switched communication is preferably embedded in either the data source 10 or the control means 11.
  • the state of the channel on which communications are occurring would be assessed based on the quality of the most recently received messages, and an adaptive scheme used in which increasing levels of error control are added to subsequent data transmissions.
  • a high rate i.e., one with a high ratio of data content to error control overhead, such as without loss of generalities, a rate 3/4 code
  • Subsequent transmissions would use lower rate codes, (e.g., without losing generalities, rate 1/2 and 1/4) if difficulty was encountered in the transmissions.
  • the same effect can be obtained by multiple transmissions of higher rate codes provided sufficient means is used to combine the partially received packets.
  • This technique often referred to as "code combining" provides the advantage of retransmission at lower rates with more efficiency, but at a cost of more receiver complexity.
  • Fig. IB there is a block diagram of an alternate embodiment of the present invention that includes an apparatus 16 having control means 11', transceiver 13, internal modem 14 and switching means 17.
  • the data source 10 and the transceiver 13 are substantially identical to the corresponding components of Fig. 1A.
  • Control means 11' performs functions substantially identical to control means 11 of Fig. 1A, but the control means 11' is capable of controlling the switching means 17.
  • the switching means 17 is used to selectively couple either external modem 15 or internal modem 14 to the input of the transceiver 13. It may not be practical to include an error control scheme in the control means 11' of Fig. IB, and therefore, the error control scheme should be implemented in either the data source 10 or external modem 15.
  • the internal modem 14 is a packet switched modem that is internal to apparatus 16, and the modem 15 could be a conventional circuit switched modem of the type commonly used in personal computers.
  • the modems 14, 15 essentially perform the same modulating/demodulating functions of modem 12 of Fig. 1A.
  • the switching means couples the internal modem 14 to the transceiver 13.
  • the switching means couples the external modem 15 to the transceiver 13.
  • a flow diagram illustrates a representative example of the software that could be used in the control means 11 of Fig. 1A of the present invention.
  • the software starts at step 20, and in step 21 a determination is made whether a packet data connection is available. In other words, a determination is made whether the apparatus of Figure 1 A can gain access to a system such as a CDPD system. If access to the packet data system is available, a determination is performed in step 40 whether there is information to evaluate the cost of the connection. If there is such information, the cost of the packet switched connection is determined in step 43 and a determination is made in step 41 whether there is an ability to evaluate the quality of the connection. If there is no such information, then a determination is made in step 41 whether there is an ability to evaluate the quality of the connection. If such capability exists, the quality of the connection is determined in step 44. If there is no such capability, then a determination is made in step 42 whether there are some other criteria for evaluating the connection. If the capability exists, then the other criteria are evaluated in step 45.
  • step 21 If it is determined in step 21 that a packet data connection is not available, then the present invention makes a determination in step 24 whether a circuit switched connection is available. In other words, a determination is made whether the present invention can gain access to a conventional circuit switched system or cellular telephone system. If access to the circuit switched system is available, a determination is performed in step 50 whether there is information to evaluate the cost of the connection. If there is such information, the cost of the circuit switched connection is determined in step 26 and a determination is made in step 51 whether there is an ability to evaluate the quality of the connection. If there is no such information, then a determination is made in step 51 whether there is an ability to evaluate the quality of the connection. If such capability exists, the quality of the connection is determined in step 27.
  • step 52 determines whether there are some other criteria for evaluating the connection. If the capability exists, then the other criteria are evaluated in step 53. If access to a switched circuit or cellular telephone system is not available, in step 24 the control means stops and waits until it is again instructed to determine the availability of either a packet data connection or a circuit switched connection. If both a circuit switched connection and packet switched connection are available, then in step 28 the control means 11 determines which connection is best. The best connection may be a result of the cost or the quality of the connection or a combination of these two factors, or some other factor.
  • step 30 a determination of an error control strategy is performed. Once the error control strategy is determined, the transmission of data can begin in step 31. During the course of data transmission the error control correction may be adaptively changed as indicated in step 32. The end of data transmission results in the performance of step 33, and the control means stops operation in step 34 of the flowchart.

Abstract

A method and apparatus for transmitting data over a wireless communication system of either the packet data type or the circuit switched type is provided. A data source (10), such as a personal computer, is connected to a specially adapted modem (12) that is capable of formatting data for transmission over either a packet switched system, such as the CDPD system, or a circuit switched system, such as a conventional cellular telephone system. A control device (11) controls the modem (12) and a transceiver (13), and it determines which communication system is the most desirable. The desirability of the communication system may be based upon cost or quality of the connection which can be established on that particular system.

Description

MODEM FOR PACKET AND CIRCUIT SWITCHED COMMUNICATION
FIELD OF THE INVENTION
The present invention relates generally to the transmission of data over a wireless communications network and, more specifically, the present invention relates to an apparatus and method for controlling a modem that can be used with either a wireless packet data communication system or a wireless circuit switched communications system.
BACKGROUND OF THE INVENTION Packet radio communication systems are wireless communications systems for transmitting data or messages. In practice, customers typically access the network through a radio frequency access device that connects the customer's data terminal to a packet switch.
A new wireless packet network called cellular digital packet data (CDPD) is being developed by a consortium of companies including regional cellular operators. The CDPD network, which is different from a conventional cellular telephone system based upon circuit switching, is expected to be a major advancement in wireless wide-area communications. The proponents of the CDPD system envision the base equipment of a CDPD cell being co-located with the base station equipment of a conventional cellular telephone system.
In 1983, the first conventional cellular telephone systems, which were designed according to the Electronic Industries Association's (El A) interim standard, were put into operation in the United States, and these early systems were known as the Advanced Mobile Phone System (AMPS). The original AMPS system is an analog system in which a plurality of base stations are connected to Mobile Telephone Switching Offices (MTSO) via land lines. The MTSO is in turn connected to the public switched telephone network (PSTN) via land lines. The base stations transmit information using radio frequency carrier signals within a cell. Mobile stations or cellular telephones operating within a particular base station cell are able to communicate with the base station, and the base station is able to connect the cellular telephone to the PSTN.
It is known that personal computers can be equipped with a specially adapted modem to transmit data over a cellular telephone system. In practice, the personal computer is connected to the special purpose modem which, in turn, is coupled to a cellular telephone via a special connector. A personal computer may also transmit data over a CDPD network using a modem specially adapted for that network. Thus, if the owner of a personal computer wishes to communicate over both networks, the owner must own both a special purpose modem for a cellular telephone system and a special purpose modem for a CDPD network.
SUMMARY OF THE INVENTION
The present invention, generally speaking, provides a method and apparatus for transmitting data or information over either a wireless packet data system, such as a CDPD system, or transmitting data over a wireless circuit switched system, such as a conventional cellular telephone system. More particularly, the present invention provides a method and apparatus that allows data to be transferred over either a wireless packet data system, such as a CDPD system, or a wireless circuit switched system, such as a conventional cellular telephone system, using the same modem. In practice, systems according to the present invention address the combination of wireless packet circuit transmission or conventional cellular telephone transmission using the same radio.
In the preferred embodiment, the present invention includes a data source, such as a personal computer or telemetry device, to generate data. The data from the data source is applied to a control means that controls a modem and a transceiver. The modem is especially adapted to work with either a CDPD system or a conventional cellular telephone system. The control means is able to select the most desirable system over which a link is to be established. For example, the control means could evaluate the quality of the connection on either system. The control means then establishes a communication link on one system which is determined to be the best, according to some criteria which may be pre-set, selected dynamically by the user or otherwise established.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention can be further understood with reference to the following description in conjunction with the appended drawings, wherein like elements are provided with the same reference numerals. In the drawings:
Figure 1A is a block diagram of the apparatus of the present invention; Figure IB is a block diagram of another embodiment of the present invention; and
Figure 2 is flowchart of the control means of Figure 1A.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In Figure 1A, a communications system includes a data source 10 which may be a personal computer, telemetry device or other means of generating data. The output from data source 10 is applied to a control means which preferably includes a suitably programmed microprocessor. The control means 11 controls a modem 12 and a transceiver 13. The modem 12 is able to adaptively transmit data over a cellular telephone infrastructure in packet switched form or in circuit switched form. In the packet switched mode, data is transmitted from the data source 10 using the modem 12 which is designed to communicate via suitably modified base station receivers and transmitters as described in, for example, the CDPD specification. In the circuit switched mode, the same radio is used to transmit data over a conventional cellular telephone system by controlling the radio to transmit and receive necessary signalling information needed to set up or to end circuit connection to a matching modem using, for example, the AMPS protocol in North America or other standards.
The control means 11 is used to determine whether the data to be transmitted from the data source 10 should be sent in packet switched form or circuit switched form based on criteria established either in manufacturing or dynamically by the user. One criterion would be the availability of the packet switched capability in the cellular infrastructure. In the dynamic case, the decision is made by the control means 11 attempting to initiate packet switched communications or by monitoring the radio channel to determine the presence or absence of control signals or traffic patterns associated with a packet communications channel. If the control means 11 determines there is no packet switched capability, then the communications would be initiated by circuit switched means over a conventional cellular telephone system.
The control means 11 also determines whether data can be transmitted in circuit switched form. In practice, the determination is based on the availability of circuit switched capability in the cellular infrastructure which is compatible with the control means. The decision is made by the control means 11 when it attempts to set up a circuit switched connection. In one scenario, the cellular infrastructure is unable to allocate circuit switched capacity (either due to the channels being busy or due to equipment failure or due to the fact that the base station with which the modem is communicating was designed to be "packet only"), then communications would be set up on the packet switched system. In another scenario, the cellular infrastructure does not support the protocol used in the modem (e.g. AMPS), and the modem is incapable of communicating using the protocol supported by the cellular infrastructure (e.g., a digital cellular protocol). In still another scenario, ancillary software resident in the data source 10 or in the control means 11 determines which means of transmission is best for the data to be transmitted based on the criterion of cost. The ancillary software or the control means may also determine which means of transmission is best for the data to be transmitted based on performance, such as response time, throughput or some other objective criteria.
The system according to the present invention preferably includes an error control strategy which is best for the circuit switched communication mode. This error control strategy can be embedded in the ancillary software of the data source 10 or the control means 11. For example, the CDPD specification specifies one particular form of error control for packet data. There is economy to be gained by using the same error control for circuit switched data where appropriate fixed modems are available for communications. The control means 11 preferably determines whether the fixed modem with which it is attempting to communicate over a circuit switched connection is able to interpret the CDPD error control scheme. If it is, then this would be the error control means of choice. Where it is not, an alternative scheme would be used.
Likewise, an error control strategy which is best for the circuit switched communication is preferably embedded in either the data source 10 or the control means 11. The state of the channel on which communications are occurring would be assessed based on the quality of the most recently received messages, and an adaptive scheme used in which increasing levels of error control are added to subsequent data transmissions. As an example, a high rate (i.e., one with a high ratio of data content to error control overhead, such as without loss of generalities, a rate 3/4 code) could be transmitted in the first transmission. Subsequent transmissions would use lower rate codes, (e.g., without losing generalities, rate 1/2 and 1/4) if difficulty was encountered in the transmissions. The same effect can be obtained by multiple transmissions of higher rate codes provided sufficient means is used to combine the partially received packets. This technique often referred to as "code combining" provides the advantage of retransmission at lower rates with more efficiency, but at a cost of more receiver complexity.
In Fig. IB there is a block diagram of an alternate embodiment of the present invention that includes an apparatus 16 having control means 11', transceiver 13, internal modem 14 and switching means 17. The data source 10 and the transceiver 13 are substantially identical to the corresponding components of Fig. 1A. Control means 11' performs functions substantially identical to control means 11 of Fig. 1A, but the control means 11' is capable of controlling the switching means 17. The switching means 17 is used to selectively couple either external modem 15 or internal modem 14 to the input of the transceiver 13. It may not be practical to include an error control scheme in the control means 11' of Fig. IB, and therefore, the error control scheme should be implemented in either the data source 10 or external modem 15.
Preferably, the internal modem 14 is a packet switched modem that is internal to apparatus 16, and the modem 15 could be a conventional circuit switched modem of the type commonly used in personal computers. The modems 14, 15 essentially perform the same modulating/demodulating functions of modem 12 of Fig. 1A. When the control means 11' determines that packet switched data is to be transmitted or received by the transceiver 13, the switching means couples the internal modem 14 to the transceiver 13. Likewise, when the control means 11 ' determines that circuit switched data is to be transmitted or received by the transceiver 13, the switching means couples the external modem 15 to the transceiver 13.
In Figure 2, a flow diagram illustrates a representative example of the software that could be used in the control means 11 of Fig. 1A of the present invention. The software starts at step 20, and in step 21 a determination is made whether a packet data connection is available. In other words, a determination is made whether the apparatus of Figure 1 A can gain access to a system such as a CDPD system. If access to the packet data system is available, a determination is performed in step 40 whether there is information to evaluate the cost of the connection. If there is such information, the cost of the packet switched connection is determined in step 43 and a determination is made in step 41 whether there is an ability to evaluate the quality of the connection. If there is no such information, then a determination is made in step 41 whether there is an ability to evaluate the quality of the connection. If such capability exists, the quality of the connection is determined in step 44. If there is no such capability, then a determination is made in step 42 whether there are some other criteria for evaluating the connection. If the capability exists, then the other criteria are evaluated in step 45.
If it is determined in step 21 that a packet data connection is not available, then the present invention makes a determination in step 24 whether a circuit switched connection is available. In other words, a determination is made whether the present invention can gain access to a conventional circuit switched system or cellular telephone system. If access to the circuit switched system is available, a determination is performed in step 50 whether there is information to evaluate the cost of the connection. If there is such information, the cost of the circuit switched connection is determined in step 26 and a determination is made in step 51 whether there is an ability to evaluate the quality of the connection. If there is no such information, then a determination is made in step 51 whether there is an ability to evaluate the quality of the connection. If such capability exists, the quality of the connection is determined in step 27. If there is no such capability, then a determination is made in step 52 whether there are some other criteria for evaluating the connection. If the capability exists, then the other criteria are evaluated in step 53. If access to a switched circuit or cellular telephone system is not available, in step 24 the control means stops and waits until it is again instructed to determine the availability of either a packet data connection or a circuit switched connection. If both a circuit switched connection and packet switched connection are available, then in step 28 the control means 11 determines which connection is best. The best connection may be a result of the cost or the quality of the connection or a combination of these two factors, or some other factor.
Once the best connection is selected, a link is established to the desired system in step 29. In step 30 a determination of an error control strategy is performed. Once the error control strategy is determined, the transmission of data can begin in step 31. During the course of data transmission the error control correction may be adaptively changed as indicated in step 32. The end of data transmission results in the performance of step 33, and the control means stops operation in step 34 of the flowchart.
The foregoing has described the principles, preferred embodiments and modes of operation of the present invention. However, the invention should not be construed as limited to the particular embodiments discussed. Instead, the above-described embodiments should be regarded as illustrative rather than restrictive, and it should "be appreciated that variations may be made in those embodiments by workers skilled in the art without departing from the scope of present invention as defined by the following claims.

Claims

What is claimed is:
1. An apparatus for transmitting data from a data source over either a wireless packet data system or a wireless circuit switched system, comprising: first means for modulating and demodulating the data in at least a first format suitable for communication over the wireless packet data system and in a second format suitable for communication over the wireless circuit switched system; a transceiver, coupled to the first means, for transmitting and receiving the data over either the wireless packet data system or the wireless circuit switched system; and means for controlling the first means and the transceiver such that the data is transmitted over a desired system.
2. An apparatus according to claim 1 wherein said means for controlling includes means for error correction.
3. An apparatus according to claim 1 wherein the data source is a computer.
4. An apparatus according to claim 1 wherein the data source is a telemetry device.
5. An apparatus according to claim 1 wherein the desired system has the least connection cost.
6. An apparatus according to claim 1 wherein the desired system has the best connection quality.
7. An apparatus according to claim 1 wherein said first means includes second means for modulating and demodulating the data in at least the first format suitable for communication over the wireless packet data system, third means for modulating and demodulating the data in the second format suitable for communication over the wireless circuit switched system, and switching means responsive to said control means for selectively coupling either the second means or the third means to the transceiver.
8. An apparatus according to claim 7 wherein said means for controlling includes means for error correction.
9. An apparatus according to claim 7 wherein the data source is a computer.
10. An apparatus according to claim 7 wherein the data source is a telemetry device.
11. An apparatus according to claim 7 wherein the desired system has the least connection cost.
12. An apparatus according to claim 7 wherein the desired system has the best connection quality.
13. A method for transmitting data from a data source over either a wireless packet data system or a wireless circuit switched system, comprising: modulating and demodulating the data with a modem in at least a first format suitable for communication over the wireless packet data system and in a second format suitable for communication over the wireless circuit switched system; transmitting and receiving the data with a transceiver over either the wireless packet data system or the wireless circuit switched system; and controlling the modem and the transceiver such that the data is transmitted over a desired system.
14. A method according to claim 13 which further includes the step of error correction.
15. A method according to claim 13 wherein the control step includes determining which system has the least connection cost.
16. A method according to claim 13 wherein the control step includes determining which system has the best connection quality.
PCT/CA1995/000147 1994-03-17 1995-03-16 Modem for packet and circuit switched communication WO1995025407A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU19435/95A AU1943595A (en) 1994-03-17 1995-03-16 Modem for packet and circuit switched communication

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US21412594A 1994-03-17 1994-03-17
US08/214,125 1994-03-17

Publications (1)

Publication Number Publication Date
WO1995025407A1 true WO1995025407A1 (en) 1995-09-21

Family

ID=22797879

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CA1995/000147 WO1995025407A1 (en) 1994-03-17 1995-03-16 Modem for packet and circuit switched communication

Country Status (2)

Country Link
AU (1) AU1943595A (en)
WO (1) WO1995025407A1 (en)

Cited By (35)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0748136A1 (en) * 1995-06-07 1996-12-11 Nokia Mobile Phones Ltd. Implementation of mutual rate adaptations in data services between GSM and DECT
WO1997028661A1 (en) * 1996-01-29 1997-08-07 Qualcomm Incorporated Automatic data service selection
EP0873620A1 (en) * 1996-10-15 1998-10-28 Motorola, Inc. Transmitting device with mobility manager and method of communicating
WO1999014929A1 (en) * 1997-09-16 1999-03-25 Mediatrix Peripherals Inc. Apparatus and method to use a conventional telephone set to make telephone calls on a packet network
WO1999016266A1 (en) * 1997-09-25 1999-04-01 Telefonaktiebolaget Lm Ericsson (Publ) Selectable packet-switched and circuit-switched services in a mobile communications network
EP0910201A2 (en) * 1997-10-17 1999-04-21 Alcatel Device and method for establishing a voice connection
WO1999022497A1 (en) * 1997-10-23 1999-05-06 Martin Daniel Nathanson Telecommunication systems
WO1999033301A1 (en) * 1997-12-18 1999-07-01 Nokia Mobile Phones Limited Resource reservation in mobile internet protocol
WO1999039533A1 (en) * 1998-01-30 1999-08-05 Detemobil Deutsche Telekom Mobilnet Gmbh Method for exchanging messages in a mobile communications network
WO2000070893A1 (en) * 1999-05-12 2000-11-23 Nokia Corporation Method for improving the quality of a telecommunication connection and a network element
EP1063832A1 (en) 1999-06-22 2000-12-27 Siemens Aktiengesellschaft A method for controlling the internet protocol data transfer of digital mobile systems
EP1070399A2 (en) * 1998-03-30 2001-01-24 Genesys Telecommunications Laboratories, Inc. Managing bandwidth on demand for internet protocol messaging with capability for transforming telephone calls from one media type to another media type
WO2001041368A1 (en) * 1999-11-29 2001-06-07 Telefonaktiebolaget Lm Ericsson (Publ) Combined cdma multi-service carrier and tdma/cdma packet carrier
WO2001067794A1 (en) * 2000-03-07 2001-09-13 Telefonaktiebolaget Lm Ericsson (Publ) Methods and apparatus for dual mode operation in a wireless communication system
GB2391763A (en) * 2002-07-03 2004-02-11 Nec Corp Data transfer system capable of selecting a low-cost call type
US6882843B1 (en) * 2000-09-14 2005-04-19 Cellemetry, Llc Multiple wireless data transport transceiver system
US6937566B1 (en) 1997-07-25 2005-08-30 Telefonaktiebolaget Lm Ericsson (Publ) Dynamic quality of service reservation in a mobile communications network
US6954453B1 (en) 1996-10-07 2005-10-11 Teles Ag Informationstechnologien Method for transmitting data in a telecommunications network and switch for implementing said method
US7110395B1 (en) 2000-10-31 2006-09-19 Cisco Technology, Inc. Method and apparatus for network telephony
US7116646B1 (en) 2000-03-07 2006-10-03 Telefonakitebolaget Lm Ericsson (Publ) CDMA internet protocol mobile telecommunications network architecture and methodology
US7197330B1 (en) * 2000-03-14 2007-03-27 Intel Corporation Dual port wireless modem for circuit switched and packet switched data transfer
US7593999B2 (en) 1997-08-26 2009-09-22 Paxgrid Telemetric Systems, Inc. Automotive telemetry protocol
US7680471B2 (en) 2006-05-17 2010-03-16 Numerex Corp. System and method for prolonging wireless data product's life
US7680505B2 (en) 2000-10-27 2010-03-16 Cellemetry, Llc Telemetry gateway
US7715431B1 (en) 2002-10-16 2010-05-11 Cisco Technology, Inc. Fallback for V.42 modem-over-internet-protocol (MoIP) gateways method and apparatus
US7783508B2 (en) 1999-09-20 2010-08-24 Numerex Corp. Method and system for refining vending operations based on wireless data
US7808981B1 (en) 2001-01-31 2010-10-05 Cisco Technology, Inc. Packet telephony across the public switched telephone network
US7880599B2 (en) 2004-01-21 2011-02-01 Numerex Corp. Method and system for remotely monitoring the operations of a vehicle
US7886344B2 (en) 2004-09-13 2011-02-08 Cisco Technology, Inc. Secure fallback network device
US7936751B2 (en) 1996-10-07 2011-05-03 Sigram Schindler Beteiligungsgesellschaft Mbh Method for transmitting data in a telecommunications network and switch for implementing said method
US8265605B2 (en) 2007-02-06 2012-09-11 Numerex Corp. Service escrowed transportable wireless event reporting system
US8560609B2 (en) 1997-08-26 2013-10-15 Paxgrid Telemetric Systems, Inc Automotive telemetry protocol
US8938062B2 (en) 1995-12-11 2015-01-20 Comcast Ip Holdings I, Llc Method for accessing service resource items that are for use in a telecommunications system
US8953771B2 (en) 2005-11-07 2015-02-10 Cisco Technology, Inc. Method and apparatus to provide cryptographic identity assertion for the PSTN
US9191505B2 (en) 2009-05-28 2015-11-17 Comcast Cable Communications, Llc Stateful home phone service

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0332818A2 (en) * 1988-03-18 1989-09-20 Motorola, Inc. Cellular telephone system with shared radio data channels
WO1991007044A1 (en) * 1989-10-31 1991-05-16 Intelligence Technology Corporation Data and voice transmission over a cellular telephone system
CA2063901A1 (en) * 1991-03-25 1992-09-26 Arunas G. Slekys Cellular data overlay system
EP0566957A1 (en) * 1992-04-13 1993-10-27 RACOTEK, Inc. Apparatus and method for overlaying data on trunked radio communications

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0332818A2 (en) * 1988-03-18 1989-09-20 Motorola, Inc. Cellular telephone system with shared radio data channels
WO1991007044A1 (en) * 1989-10-31 1991-05-16 Intelligence Technology Corporation Data and voice transmission over a cellular telephone system
CA2063901A1 (en) * 1991-03-25 1992-09-26 Arunas G. Slekys Cellular data overlay system
EP0566957A1 (en) * 1992-04-13 1993-10-27 RACOTEK, Inc. Apparatus and method for overlaying data on trunked radio communications

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
MILLER: "CDPD Brightens Prospects for Wireless Data", DATA COMMUNICATIONS, vol. 22, no. 13, 21 September 1993 (1993-09-21), NEW YORK US, pages 23 - 24, XP000396757 *

Cited By (69)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1996041490A1 (en) * 1995-06-07 1996-12-19 Nokia Mobile Phones Ltd. Implementation of mutual rate adaptations in data services between gsm and dect
US6081534A (en) * 1995-06-07 2000-06-27 Nokia Mobile Phones, Ltd. Implementation of mutual rate adaptations in data services between GSM and DECT
AU716363B2 (en) * 1995-06-07 2000-02-24 Vringo Infrastructure, Inc. Implementation of mutual rate adaptations in data services between GSM and DECT
EP0748136A1 (en) * 1995-06-07 1996-12-11 Nokia Mobile Phones Ltd. Implementation of mutual rate adaptations in data services between GSM and DECT
US8938062B2 (en) 1995-12-11 2015-01-20 Comcast Ip Holdings I, Llc Method for accessing service resource items that are for use in a telecommunications system
WO1997028661A1 (en) * 1996-01-29 1997-08-07 Qualcomm Incorporated Automatic data service selection
US5940383A (en) * 1996-01-29 1999-08-17 Qualcomm Incorporated Automatic data service selection
US8175083B2 (en) 1996-10-07 2012-05-08 Sigram Schindler Beteiligungsgesellschaft Mbh Method for transmitting data in a telecommunications network and switch for implementing said method
US6954453B1 (en) 1996-10-07 2005-10-11 Teles Ag Informationstechnologien Method for transmitting data in a telecommunications network and switch for implementing said method
US7936751B2 (en) 1996-10-07 2011-05-03 Sigram Schindler Beteiligungsgesellschaft Mbh Method for transmitting data in a telecommunications network and switch for implementing said method
US7145902B2 (en) 1996-10-07 2006-12-05 Teles Ag Informations-Technologien Method for transmitting data in a telecommunications network and switch for implementing said method
EP0873620A4 (en) * 1996-10-15 2002-01-02 Motorola Inc Transmitting device with mobility manager and method of communicating
EP0873620A1 (en) * 1996-10-15 1998-10-28 Motorola, Inc. Transmitting device with mobility manager and method of communicating
US6937566B1 (en) 1997-07-25 2005-08-30 Telefonaktiebolaget Lm Ericsson (Publ) Dynamic quality of service reservation in a mobile communications network
US8560609B2 (en) 1997-08-26 2013-10-15 Paxgrid Telemetric Systems, Inc Automotive telemetry protocol
US7593999B2 (en) 1997-08-26 2009-09-22 Paxgrid Telemetric Systems, Inc. Automotive telemetry protocol
US6944151B1 (en) 1997-09-16 2005-09-13 Mediatrix Telecom, Inc. Apparatus and method to use a conventional telephone set to make telephone calls on a packet network
WO1999014929A1 (en) * 1997-09-16 1999-03-25 Mediatrix Peripherals Inc. Apparatus and method to use a conventional telephone set to make telephone calls on a packet network
WO1999016266A1 (en) * 1997-09-25 1999-04-01 Telefonaktiebolaget Lm Ericsson (Publ) Selectable packet-switched and circuit-switched services in a mobile communications network
US6608832B2 (en) 1997-09-25 2003-08-19 Telefonaktiebolaget Lm Ericsson Common access between a mobile communications network and an external network with selectable packet-switched and circuit-switched and circuit-switched services
AU742647B2 (en) * 1997-09-25 2002-01-10 Telefonaktiebolaget Lm Ericsson (Publ) Selectable packet-switched and circuit-switched services in a mobile communications network
EP0910201A2 (en) * 1997-10-17 1999-04-21 Alcatel Device and method for establishing a voice connection
AU745083B2 (en) * 1997-10-17 2002-03-14 Alcatel Internet/PSTN call connection arrangement
US6426942B1 (en) 1997-10-17 2002-07-30 Alcatel Device and method for establishing a call connection
EP0910201A3 (en) * 1997-10-17 2003-07-16 Alcatel Device and method for establishing a voice connection
DE19745961A1 (en) * 1997-10-17 1999-04-22 Cit Alcatel Device and method for establishing a call connection
WO1999022497A1 (en) * 1997-10-23 1999-05-06 Martin Daniel Nathanson Telecommunication systems
US6487595B1 (en) 1997-12-18 2002-11-26 Nokia Mobile Phones Limited Resource reservation in mobile internet protocol
WO1999033301A1 (en) * 1997-12-18 1999-07-01 Nokia Mobile Phones Limited Resource reservation in mobile internet protocol
WO1999039533A1 (en) * 1998-01-30 1999-08-05 Detemobil Deutsche Telekom Mobilnet Gmbh Method for exchanging messages in a mobile communications network
EP1070399A2 (en) * 1998-03-30 2001-01-24 Genesys Telecommunications Laboratories, Inc. Managing bandwidth on demand for internet protocol messaging with capability for transforming telephone calls from one media type to another media type
EP1070399A4 (en) * 1998-03-30 2004-04-21 Genesys Telecomm Lab Inc Managing bandwidth on demand for internet protocol messaging with capability for transforming telephone calls from one media type to another media type
EP1177698A1 (en) * 1999-05-12 2002-02-06 Nokia Corporation Method for improving the quality of a telecommunication connection and a network element
WO2000070893A1 (en) * 1999-05-12 2000-11-23 Nokia Corporation Method for improving the quality of a telecommunication connection and a network element
EP1909454A1 (en) * 1999-06-22 2008-04-09 Siemens Aktiengesellschaft A method for controlling the internet protocol data transfer of digital mobile systems
EP1063832A1 (en) 1999-06-22 2000-12-27 Siemens Aktiengesellschaft A method for controlling the internet protocol data transfer of digital mobile systems
US7783508B2 (en) 1999-09-20 2010-08-24 Numerex Corp. Method and system for refining vending operations based on wireless data
US6879580B1 (en) 1999-11-29 2005-04-12 Telefonaktiebolaget Lm Ericsson Combined CDMA multi-service carrier and TDMA/CDMA packet carrier
WO2001041368A1 (en) * 1999-11-29 2001-06-07 Telefonaktiebolaget Lm Ericsson (Publ) Combined cdma multi-service carrier and tdma/cdma packet carrier
US7054290B1 (en) 2000-03-07 2006-05-30 Telefonaktiebolaget Lm Ericsson (Publ) Methods and apparatus for dual mode operation in a wireless communication system
US7116646B1 (en) 2000-03-07 2006-10-03 Telefonakitebolaget Lm Ericsson (Publ) CDMA internet protocol mobile telecommunications network architecture and methodology
WO2001067794A1 (en) * 2000-03-07 2001-09-13 Telefonaktiebolaget Lm Ericsson (Publ) Methods and apparatus for dual mode operation in a wireless communication system
US7197330B1 (en) * 2000-03-14 2007-03-27 Intel Corporation Dual port wireless modem for circuit switched and packet switched data transfer
US6882843B1 (en) * 2000-09-14 2005-04-19 Cellemetry, Llc Multiple wireless data transport transceiver system
US8543146B2 (en) 2000-10-27 2013-09-24 Cellemetry, Llc Method and system for efficiently routing messages
US7680505B2 (en) 2000-10-27 2010-03-16 Cellemetry, Llc Telemetry gateway
US8060067B2 (en) 2000-10-27 2011-11-15 Cellemetry Llc Method and system for efficiently routing messages
US8903437B2 (en) 2000-10-27 2014-12-02 Numerex Corp. Method and system for efficiently routing messages
US7110395B1 (en) 2000-10-31 2006-09-19 Cisco Technology, Inc. Method and apparatus for network telephony
US7808981B1 (en) 2001-01-31 2010-10-05 Cisco Technology, Inc. Packet telephony across the public switched telephone network
GB2391763A (en) * 2002-07-03 2004-02-11 Nec Corp Data transfer system capable of selecting a low-cost call type
US8032607B2 (en) 2002-07-03 2011-10-04 Nec Corporation Data transfer system capable of selecting a low-cost call type
GB2391763B (en) * 2002-07-03 2006-03-08 Nippon Electric Co Data transfer system capable of selecting a low-cost call type
US7715431B1 (en) 2002-10-16 2010-05-11 Cisco Technology, Inc. Fallback for V.42 modem-over-internet-protocol (MoIP) gateways method and apparatus
US7880599B2 (en) 2004-01-21 2011-02-01 Numerex Corp. Method and system for remotely monitoring the operations of a vehicle
US8269618B2 (en) 2004-01-21 2012-09-18 Numerex Corp. Method and system for remotely monitoring the location of a vehicle
US9084197B2 (en) 2004-01-21 2015-07-14 Numerex Corp. Method and system for interacting with a vehicle over a mobile radiotelephone network
US7936256B2 (en) 2004-01-21 2011-05-03 Numerex Corp. Method and system for interacting with a vehicle over a mobile radiotelephone network
US7886344B2 (en) 2004-09-13 2011-02-08 Cisco Technology, Inc. Secure fallback network device
US9582380B2 (en) 2004-09-13 2017-02-28 Cisco Technology, Inc. Secure fallback network device
US9027095B2 (en) 2004-09-13 2015-05-05 Cisco Technology, Inc. Secure fallback network device
US8953771B2 (en) 2005-11-07 2015-02-10 Cisco Technology, Inc. Method and apparatus to provide cryptographic identity assertion for the PSTN
US8041383B2 (en) 2006-05-17 2011-10-18 Numerex Corporation Digital upgrade system and method
US7680471B2 (en) 2006-05-17 2010-03-16 Numerex Corp. System and method for prolonging wireless data product's life
US8868059B2 (en) 2006-05-17 2014-10-21 Numerex Corp. Digital upgrade system and method
US8483748B2 (en) 2006-05-17 2013-07-09 Numerex Corp. Digital upgrade system and method
US8855716B2 (en) 2007-02-06 2014-10-07 Numerex Corp. Service escrowed transportable wireless event reporting system
US8265605B2 (en) 2007-02-06 2012-09-11 Numerex Corp. Service escrowed transportable wireless event reporting system
US9191505B2 (en) 2009-05-28 2015-11-17 Comcast Cable Communications, Llc Stateful home phone service

Also Published As

Publication number Publication date
AU1943595A (en) 1995-10-03

Similar Documents

Publication Publication Date Title
WO1995025407A1 (en) Modem for packet and circuit switched communication
US5533029A (en) Cellular digital packet data mobile data base station
US6526034B1 (en) Dual mode subscriber unit for short range, high rate and long range, lower rate data communications
EP0521610B1 (en) Digital cellular overlay network
US5898920A (en) Data communication using a dual mode radiotelephone
US7024222B2 (en) Dual mode unit for short range, high rate and long range, lower rate data communications
US6091967A (en) Scalable radio platform
US6240077B1 (en) Dynamic wireless multiplexing — switching hub for providing two-way communications with subscriber units
EP0840533B1 (en) A method and system for communicating with remote units in a communication system
EP0239093A2 (en) Multiple access radio telephone system selectively operating on full-duplex and half-duplex modes
US20060092877A1 (en) Data transport in GSM system
US6130883A (en) Method and apparatus for voice packet communications
US20020049036A1 (en) Wireless phone/data jack using 49 mhz rf technology
JP3444780B2 (en) Wireless data communication method and wireless data communication device
US20150139216A1 (en) Discontinuous Transmission CDMA System
JP3226751B2 (en) Mobile communication system
JP3368047B2 (en) Relay communication device
JP3136884B2 (en) Digital mobile communication system and data transmission method
JPH0352340A (en) Mobile object communication system
WO2001028112A1 (en) Wireless phone/data jack using 900 mhz rf technology

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AM AT AU BB BG BR BY CA CH CN CZ DE DK EE ES FI GB GE HU JP KE KG KP KR KZ LK LR LT LU LV MD MG MN MW MX NL NO NZ PL PT RO RU SD SE SG SI SK TJ TT UA UG US UZ VN

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): KE MW SD SZ UG AT BE CH DE DK ES FR GB GR IE IT LU MC NL PT SE BF BJ CF CG CI CM GA GN ML MR NE SN TD TG

121 Ep: the epo has been informed by wipo that ep was designated in this application
DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
REG Reference to national code

Ref country code: DE

Ref legal event code: 8642

122 Ep: pct application non-entry in european phase
NENP Non-entry into the national phase

Ref country code: CA