CA2090710C - Method and system for enhanced data transmission in a cellular telephone system - Google Patents
Method and system for enhanced data transmission in a cellular telephone systemInfo
- Publication number
- CA2090710C CA2090710C CA002090710A CA2090710A CA2090710C CA 2090710 C CA2090710 C CA 2090710C CA 002090710 A CA002090710 A CA 002090710A CA 2090710 A CA2090710 A CA 2090710A CA 2090710 C CA2090710 C CA 2090710C
- Authority
- CA
- Canada
- Prior art keywords
- cellular telephone
- data
- telephone system
- relatively short
- data packets
- 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.)
- Expired - Fee Related
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Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W28/00—Network traffic management; Network resource management
- H04W28/02—Traffic management, e.g. flow control or congestion control
- H04W28/06—Optimizing the usage of the radio link, e.g. header compression, information sizing, discarding information
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W28/00—Network traffic management; Network resource management
- H04W28/02—Traffic management, e.g. flow control or congestion control
- H04W28/06—Optimizing the usage of the radio link, e.g. header compression, information sizing, discarding information
- H04W28/065—Optimizing the usage of the radio link, e.g. header compression, information sizing, discarding information using assembly or disassembly of packets
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W28/00—Network traffic management; Network resource management
- H04W28/02—Traffic management, e.g. flow control or congestion control
- H04W28/10—Flow control between communication endpoints
- H04W28/14—Flow control between communication endpoints using intermediate storage
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
- Y02D30/00—Reducing energy consumption in communication networks
- Y02D30/70—Reducing energy consumption in communication networks in wireless communication networks
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Mobile Radio Communication Systems (AREA)
- Data Exchanges In Wide-Area Networks (AREA)
- Use Of Switch Circuits For Exchanges And Methods Of Control Of Multiplex Exchanges (AREA)
- Telephonic Communication Services (AREA)
Abstract
A method and system are disclosed for enhanced data transmission within a cellular telephone system having multiple assigned voice channels separated by adjacent buffer voice channels. A data processing terminal is utilized to divide the data stream into multiple relatively short data packets which are then sequentially transmitted within alternate adjacent buffer voice channels. By switching from one adjacent buffer voice channel to a subsequent adjacent buffer voice channel, in a predetermined and repetitive order, as each data packet is transmitted, the amount of interference experienced in any one assigned voice channel is minimized. Synchronization between adjacent data packets may be achieved by either utilizing adjacent buffer voice channels in a predetermined and repetitive order or by concatenating an indication of the next buffer voice channel utilized with each data packet. A
synchronization packet may also be included with each data packet to permit synchronization between adjacent data packets at the receiver.
synchronization packet may also be included with each data packet to permit synchronization between adjacent data packets at the receiver.
Description
~: -METHOD AND SYSTE~ FOR ENHANCED DATA TRANSMISSION
IN A OE LLULAR TEL~r ~ SYSTEM
.
BACKGROUND OF THE INVENTION
l. Technical Eield:
The pre~ent invention relate~ in general to impLo~rnts in datà transmission sy~tems and in particular to ^~h~ced method~ and systems for data transmission in a cellular telephone' sy~tem. Still more particularly, the present lnvention relates to an improved method and system for trAnsmitting data packets within alternate adjacent buffcr voice channels in a cellular telephone system.
IN A OE LLULAR TEL~r ~ SYSTEM
.
BACKGROUND OF THE INVENTION
l. Technical Eield:
The pre~ent invention relate~ in general to impLo~rnts in datà transmission sy~tems and in particular to ^~h~ced method~ and systems for data transmission in a cellular telephone' sy~tem. Still more particularly, the present lnvention relates to an improved method and system for trAnsmitting data packets within alternate adjacent buffcr voice channels in a cellular telephone system.
2. DescriFtion of the Related Art:
~ Data c~ un1cation between modern computer device~
i~ typically accomplished utilizing a modulator/demodulator or ~o-called "modem" which is utilized to convert digita~
signal~ within a data processing ~ystem to analog signals for tr~n~mittal over existing communication links.
Additionally, ~uch devices convert received analog signals to digital signals for utilization by a data processing system. In the past most distribllted computer networks have been coupled together utilizing exi~ting telephone land line systems, or specialized wiring; l1owever, modern distributed data processing system~ often ~Itilize more sophisticated means of CG in1cation. -, - For example, the decreasing cost of cellular cc In~cation equipment has res~llted in the utilization of that technology to couple together computer~ without the nece~ity of access to a telephone line outlet. Thi~
j -particular technology is particularly effective in comblnation with small portable battery powered laptop or notebook-computer~ in which the necessary modem and cellular communication circuitry are miniaturized and provided in an integral fa~hion within thè computer it~elf. Thus, an operator utilizing ~uch a computer may initiate communications and transfer data between hi~ or her computer and a di~tributed data processing sy~tem without the nece~ity of acce~s to either telephone lines or power , ~ !
~ ,~
2090710 ``
~' ` , ,, line~. Examples of such portable computer# include the Intornational Business Machines Corporation L40SX and the Model No. 9075 PCradio~ which may ~be utilized for wirele,#s communication by attaching a radio device. Radio devices suGh a~ cellular telephone tran~ceivers or ARDIS radio devlco~ may be utilized.
:
Mobile data terminals which compri~e battery powered data proces~ing systems with cellular transceiver network8 may be utilized to provide packet-switched access to ~ervices on remote ho~t~ or other mobile data terminals by tran~mltting data via a cellular telephone system. Such ~y~tem~ typlcally ~upport both voice and other analog trafic and tho operation of such system# may be continued at full capacity, without awareness or interaction, with a data tran~mis~ion system. Each mobile data terminal in such a 8y8tem generally consi~ts of an application component and a COI ~cation6 component, together, referred to as a "~ub w riber unit." Data is accepted and forwarded to and from eub~criber units by a Mobile Data Base System (MD8S) which manage~ the allocation of channels within a cellular telephone system.
.
In known prior art data transmission systems which utilize a cellular telephone æystem, comm~lnication between a subscriber unit and the MD BS talces place over a pair of ch~el~. Sub~criber units receive data from the MDBS over a "forward channel" and transmit data to the M~BS over a "reverso channel." The two channels ntilized are related a#
set forth in the EIA/TIA-553 standard. An MDBS may maintain several forward channels simultaneously for c- Jnication with different sets of subscriber ~Inits and a given reverse ~hAnnel may be multiplexed among subscriber unit~ tuned to the corrosponding forward channel. When a channel pair which i~ utilized for data transmission is reassigned to a new analog cellular circuit, the MDBS and ~ubscriber units switch to another free channel and continue to operate in a procedure known as "channel hopping."
While such systems permit the transfer of data utilizing analog voice channels within a cellular telephone -sy~tem, the increa~ed utilization of cellular telephone ~y8tem8 for data transmi~ion has reæulted in an increased d~ ~n~ on ~uch system6. As those skilled in the art will appreciate in such systems assigned voice ch~nnels are utillzed for communication; however, each assigned voice c~nnel i8 surrounded by vacant adjacent channel~ which are utilized to minimize interference between ad;acent channel~.
It ha~ recently been proposed that these vacant adjacent voice channels be utilized for data transmission by utilizing a very narrow band modulated carrier within one of thes0 adjacent channels. By r-lnning such a data transmi~sion at very low speed~ and signal strength, the interference With adjacent a~æiqned voice chPnel~ may be minimlzed; however, the resultant data transmis~ion rates are generally not ~uficient for modern data transmission ~y~tems.
- It should therefore be apparent that a need exists ~ for a method and system which will enhance the efficiency of dàta transmission within a cellular telephone system.
.
SUMMARY OF THE INVENTION
- It is therefore one object of the present invention to provide an improved data transmission system.
It is another object of the present invention to provide an enhanced method and sy~tem for data transmission within a cellular telephone system.
It i8 yet another object of the present invèntion to provide an improved method and system for transmitting data pac~ets within alternate adjacent buffer voice channels in a cellular telephone ~ystem in a manner which minimizes intsrference with adjacent assigned voice channels.
The foregoing objects are achieved as is now described. The method and system of the present invention may be utilized for enhanced data tran~mi sion within a cellular telep~one system having multiple a~signed voice ch~nnels ~eparated by ad~acent buffer voice ch~nels. A
-, ~ BC9-92-074 2 09~ 710 data processing terminal is utilized to divide the data stream into multiple relatively short data packets which are then sequentially transmitted within alternate adjace,nt buffer voice channels. By switching from one adjacent buffer volce çh~nnel to a subsequent ad;acent buffer voice channel, in a predetermined and repetitive order, as each data packet i~ transmitted, the amount of interference experienced in any she as signed voice- channel i8 minimized.
Synchronization between ad~acent data packets may be achieved by either utilizing adjacent buffer voice channels in a predetermined and repetitive order or by concatenating an indication o the next buffer volce channel utilized with each data packet. A synchronization packet may also be included with each data packet to permit synchronization between ad~acent data packets at the receiver.
.
BRIEF DESCRIPTIQN OF THE DRAWING
The novel features believed characteristic of the inventlon are set forth in the appended claims. The inv~ntion itself however, as well a.s a preferred mode of u~e, further objects and advantage.g thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in con~unctlon with the accompanying drawiJIgs, wherein:
~ .
~ I
Figure 1 i8~ a parl:ially schematic -pictorial representation of a distributed data processing system which, may be utilized for enhanced data transmis~ion within a cellular telephone system in accordance with the method and system o the present invention;
I, Figure 2 is a pictorial representation of a plurality of assigned volce channels separated by adjacent buffer voice channels;
Figure 3 is a`high level block diagram of a data proces~ing sy~tem which may be utilized for enhanced data transmi~sion in accordance with the method and system of the present Invention snd , , .
Figure6 4a and 4b illu~trate alternate embodiments of data packets which may be utilized for enhanced data transmission in accordance with the method and syætem of ~he present lnvention.
DETAILED DESCRIPTION OF PR~ERRED EMBODIMENT
-With reference now to the figures and in particular with reference to ~igure 1, there i~ depicted a partially schématic pictorial repre~entation of a di~tributed data proce~sing system 10 which may be utilized for enh~ced data tran~mission within a cellular telephone system ln accordance with the method and' ~ystem of the present invention. Upon reference to the foregoing those - skilled in the art will appreciate that while distributed data processlng system 10 i~ i]]alætrated as including only two computers, typically such distributed data processing ~ystems include a large number of computers distributed over a -,wide geographic area.- As illustrated,; one of the computer~ within distributed data processing system 10 is a portable computer 12. Portable computer 12 i8 typically a battery powered computer which includes a low power display system 16 which preerably provides a display screen 18 which may be implemented utilizing a liquid crystal display (LCD~, a gas plasma display, or any other suitable technology display. Keyboard ~4 is ~lso provided which enable~ the user to acces~ and modify data stored within portable computer -12 in a manner well known in the art.
As those skill'ed in the art will appreciate it is increasingly common for computer~ such as portable computer 12 to include therein a miniature cellular telephone' transce~ver (not shown~ which is provided in con~unction with a modem. One example of a portable computer equipped with a combination modem/cellular telephone which may be utilized to implement portable computer 12 is- the International Business Machines Corporation Model No. 9075 PCradio. Those skilled in the art will appreciate that a modem is a 'device which may be utilized to convert digital data from a computer to an analog signal which may be tran~mitted via a teleco~ cations sy~tems. Additionally,`
, 209~7~0 such devices convert received analog signals from a telecommunications line to digital data which may be utilized by a computer. As i~ typical in ~uch systems" a cellular telephone transmits a radio frequency signal via Antenna 20 which may be received and relayed via multiple cellular system antenna 22. Thus, digital data within portable computer 12 may be converted into a series of analog signals and transmitted, via a cellular telephone and multiple intervening repeaters to a telephone system 24, in a manner well known to thoæe skilled in this art.
I
Analog ~ignals thus transmitted may be received by the ` telephone sy~tem and tran~mitted, via an ordinary telè~ho~e land line 26 to a computer 28 within distributed data processing system 10. While computer 28 is depicted as a personal computer, tho~e skilled in the art will appreciate that computer 28 may be implemented utilizing a workstation, terminal or mainframe computer, as de~ired.
Typically, computer 28 will also include a modem device permitting data from portable computer 12-to be transmitted to an* received by computer 28 an~ computer 28 may also be linked to portable computer 12 utilizing cellular technology, rather than telepholle land lines.
hu~, as those skil]ed ill the art will appreciate upon reference to the foregoing, the transmi~sion of data from portable computer 12 to comp~lter 28 utilizing depicted cellular telephone 'technology is well known in the art.
However, as the d~l4n~ on ce].lular telephone ~ystems ~, $ncrea~e and the amount of data being transmitted utilizing computers of the type depicted within Figure 1 increases, the ~- ~n~ on the available channels within a cellular telepho~e system become much greater. Thus, it should be apparent that a need exists for a method and ~ystem whereby data may be transmitted via a cellular telephone system in, an e~Anced mode without degrading the ability of the cellular telephone system to accommodate voice transml~ion~.
, Referring now to Figure 2, there is depicted a pictorial representation of a plurality of assigned voice .
BC9-92-07~ 7 {
..
chAnnels separated by adjacent buffer voice channels in a manner typically provided within a cellular telephone system. As depicted, assigned volce channels 42, 4~, ~6, 48, 50, and 52 are pictorially illustrated within a frequency spectrum and are separated, as depicted, by ad~acent buffer voice channels 54, 56, S8, 60, and-62. This i8 typically accompli~hed in order to minimize the interf~rence between two assigned voice channels which are transmitting or receiving multiple cellular telephone tran~mi~sions simultaneousl.y. Thus, by providing adjacent buffer voice c~Annel~ between ad~acent assigned voice c~A~ls, the amount of "cross talk" or other types of interference present within assigned voice channel~ may be effectively minimized.
As discussed above, it has been proposed to util$ze these adjacent buffer voice channels within the cellular telephone system for transmission of data by utilizing a low data rate, low power data transmission system; however, such systems are not effective in that the interference with ad~acent assi.gned voice channels is fairly great when the power or data rate withi.n an associated data tran~mission channel exceeds a preselected minimum. Thus, it should be apparent that a need exists for a method and ~ystem which will permit the e~lha~-ced transmis~ion of data within a cellular telephone sy~.em utilizing these adjacent bufer voice channels.
-.
The -method and system of the present inYention yields much greater data speeds and minimal interference with assigned voice channels within a cellular telephone system by implementing a "spread ~pectrum" data tran~ceiver within multiple adjacent buffer voice channels. That is, a data stream i~ divided into relatively short data packets which are se~uentially transmitted via alternate adjacent buffer voice channe}s in a predetermined -and repetitive order. Thus, the presence of data within an adjacent buffer voice channel is minimized for a particular as~igned voice, ch~nnel and the effect of interference caused by transmission of that data i.9 effectively minimized.
Additlonally, the energy density wit.hin each adjacent buffer 209~710 ~'. ' voice channel is restrained to fairly insignificant levels.
Thi~ may -be accomplished by utilizing a data processing sy~tem implemented in accordance with the method and sys~em of the present invention. A hi~h level block diagram of such a data processing system is depicted within Figure 3.
As illustrated, Figure 3 depicts~ a processor 66 which i~ utilized to control ~ynthesiæer 68. Synthesizer 68 controlo the transmit and receive frequenciés o~ transmitter 70 and receiver 72 in accordance with E IA/TIA 553 Cellular Telephone Standards. ~ata from proceRsor 66 which is to be tran~mitted by tran~mitter 70 is coupled to transmitter 70 and tran~mitted in relatively short data packets within alternating adjacent buffer voice channels in the manner de~cribed above. The output of ~transmitter 70 i8 coupled, via duplexer 74, to antenna 20 for transmission within the cellular telephsne system. -,`
Similarly, relatively short data packets may be received via antenna 20 and duplexer 74 and coupled to receiver 72. Recei'ver 72 is preferably selectively tuned to a ~erle- of predetermined adj'acent b~1ffer voice channels to receive each sequential data pac1cet and that data is coupled from receiver 72 to proceæsor h6. In this manner, a data stream may be transmitted and/or received within a cellular telephone system by dividing that data stream into a plurallty of relatively short data packets and sequentially tran#mittlng and receiving those data' packèts within àlternate adjacent buffer voice channel~ which are present between asslgned voice ~hannel~' throughout a standard cellular telephone system.
Referring now to Figures 4a and 4b, there are illu~trated two alternate embodiments of data packets which may be utilized for synchronization in the enhanced data packet transmls~ion system of the present invention. As depicted in Figure 4a, a data frame 80 is illustrated which includes a synchronization packet 82 and a data packet 84.
The length of data packet 84 is preferably fixed; however, this length may be set by the system operator. The length of data packet 84 is chosen to minimize -the amount of .
, . BC9-92-074 9 ~. I
- interference within an adjacent assigned voice channel.
Data packet 84 is preferably relatively short; however, data`
packet 84 is substantially longer than ~ynchronizat~on packet ~2.
- , - - When utilizing the data frame 80 as depicted in Figure 4a, data packet~ are preferably transmitted utilizing multipl- adjacent buffer voice chamlels in a predetermined and repet$tive order throughout all available adjacent buffer voice channels. Thus, a remote terminal may tune to a particu}ar adjacent buffer voi.ce channel and await the reception of a data packet. Thereafter, the remote terminal may tune to ~ub~equent adjacent b~tffer voice channel~ in the predetermined and repetitive order necessary to receive the data stream.
An alternate data packet format is depicted at Figure 4b wherein data frame 88 includes a synchronization packet 90, a "next channel" packet 92 and a data packet 94.
In a m~nner similar to that described above, this data packet may be utilized to tran~mit data within a cellular telephone ~ystem while minimizing interference in adjacent assigned voice channel~ without lequiri.llg a predetermined - and repetitive utilization of adjacent buffer voice ch~n~el~. By utl}izing "next channel" packet 92 to indicate the ad~acent buffer voice chantlel within which t he ~ubsequent data packet will be contained the remote terminal receiving such a data packet may rapidly and efficiently tune to the next appropriate adjacellt buffer voice channel.
Upon reference to the foregoing those skilled in the art will appreciate that by dividing a data stream into relatively short data packets and ~equentially transmitting tho~e data packets utilizing multiple adjacent buffer voice ch~nnel8 within a standard cellular telephone sy~tem, the amount of interference within an assigned voice channel may be min$mized while maintaining relatively high data rates and signal strengths.
While the invention has been particularly shown and descrlbed wlth reference to a preferred embod1ment, it ,.
.
20so7lo . BC9-92-074 10 will be understood by thos~ ~kiIled in the art that various c~ngeo in form and detail may be made therein without departlng from the ~plrlt and ^cope of the Invontlon.
`
, -, , , ,' '', ~ ' ' ' ' ' ,", ' ' .
~ ' :
`
~ ` ' . i ' .
` ` ' ,
~ Data c~ un1cation between modern computer device~
i~ typically accomplished utilizing a modulator/demodulator or ~o-called "modem" which is utilized to convert digita~
signal~ within a data processing ~ystem to analog signals for tr~n~mittal over existing communication links.
Additionally, ~uch devices convert received analog signals to digital signals for utilization by a data processing system. In the past most distribllted computer networks have been coupled together utilizing exi~ting telephone land line systems, or specialized wiring; l1owever, modern distributed data processing system~ often ~Itilize more sophisticated means of CG in1cation. -, - For example, the decreasing cost of cellular cc In~cation equipment has res~llted in the utilization of that technology to couple together computer~ without the nece~ity of access to a telephone line outlet. Thi~
j -particular technology is particularly effective in comblnation with small portable battery powered laptop or notebook-computer~ in which the necessary modem and cellular communication circuitry are miniaturized and provided in an integral fa~hion within thè computer it~elf. Thus, an operator utilizing ~uch a computer may initiate communications and transfer data between hi~ or her computer and a di~tributed data processing sy~tem without the nece~ity of acce~s to either telephone lines or power , ~ !
~ ,~
2090710 ``
~' ` , ,, line~. Examples of such portable computer# include the Intornational Business Machines Corporation L40SX and the Model No. 9075 PCradio~ which may ~be utilized for wirele,#s communication by attaching a radio device. Radio devices suGh a~ cellular telephone tran~ceivers or ARDIS radio devlco~ may be utilized.
:
Mobile data terminals which compri~e battery powered data proces~ing systems with cellular transceiver network8 may be utilized to provide packet-switched access to ~ervices on remote ho~t~ or other mobile data terminals by tran~mltting data via a cellular telephone system. Such ~y~tem~ typlcally ~upport both voice and other analog trafic and tho operation of such system# may be continued at full capacity, without awareness or interaction, with a data tran~mis~ion system. Each mobile data terminal in such a 8y8tem generally consi~ts of an application component and a COI ~cation6 component, together, referred to as a "~ub w riber unit." Data is accepted and forwarded to and from eub~criber units by a Mobile Data Base System (MD8S) which manage~ the allocation of channels within a cellular telephone system.
.
In known prior art data transmission systems which utilize a cellular telephone æystem, comm~lnication between a subscriber unit and the MD BS talces place over a pair of ch~el~. Sub~criber units receive data from the MDBS over a "forward channel" and transmit data to the M~BS over a "reverso channel." The two channels ntilized are related a#
set forth in the EIA/TIA-553 standard. An MDBS may maintain several forward channels simultaneously for c- Jnication with different sets of subscriber ~Inits and a given reverse ~hAnnel may be multiplexed among subscriber unit~ tuned to the corrosponding forward channel. When a channel pair which i~ utilized for data transmission is reassigned to a new analog cellular circuit, the MDBS and ~ubscriber units switch to another free channel and continue to operate in a procedure known as "channel hopping."
While such systems permit the transfer of data utilizing analog voice channels within a cellular telephone -sy~tem, the increa~ed utilization of cellular telephone ~y8tem8 for data transmi~ion has reæulted in an increased d~ ~n~ on ~uch system6. As those skilled in the art will appreciate in such systems assigned voice ch~nnels are utillzed for communication; however, each assigned voice c~nnel i8 surrounded by vacant adjacent channel~ which are utilized to minimize interference between ad;acent channel~.
It ha~ recently been proposed that these vacant adjacent voice channels be utilized for data transmission by utilizing a very narrow band modulated carrier within one of thes0 adjacent channels. By r-lnning such a data transmi~sion at very low speed~ and signal strength, the interference With adjacent a~æiqned voice chPnel~ may be minimlzed; however, the resultant data transmis~ion rates are generally not ~uficient for modern data transmission ~y~tems.
- It should therefore be apparent that a need exists ~ for a method and system which will enhance the efficiency of dàta transmission within a cellular telephone system.
.
SUMMARY OF THE INVENTION
- It is therefore one object of the present invention to provide an improved data transmission system.
It is another object of the present invention to provide an enhanced method and sy~tem for data transmission within a cellular telephone system.
It i8 yet another object of the present invèntion to provide an improved method and system for transmitting data pac~ets within alternate adjacent buffer voice channels in a cellular telephone ~ystem in a manner which minimizes intsrference with adjacent assigned voice channels.
The foregoing objects are achieved as is now described. The method and system of the present invention may be utilized for enhanced data tran~mi sion within a cellular telep~one system having multiple a~signed voice ch~nnels ~eparated by ad~acent buffer voice ch~nels. A
-, ~ BC9-92-074 2 09~ 710 data processing terminal is utilized to divide the data stream into multiple relatively short data packets which are then sequentially transmitted within alternate adjace,nt buffer voice channels. By switching from one adjacent buffer volce çh~nnel to a subsequent ad;acent buffer voice channel, in a predetermined and repetitive order, as each data packet i~ transmitted, the amount of interference experienced in any she as signed voice- channel i8 minimized.
Synchronization between ad~acent data packets may be achieved by either utilizing adjacent buffer voice channels in a predetermined and repetitive order or by concatenating an indication o the next buffer volce channel utilized with each data packet. A synchronization packet may also be included with each data packet to permit synchronization between ad~acent data packets at the receiver.
.
BRIEF DESCRIPTIQN OF THE DRAWING
The novel features believed characteristic of the inventlon are set forth in the appended claims. The inv~ntion itself however, as well a.s a preferred mode of u~e, further objects and advantage.g thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in con~unctlon with the accompanying drawiJIgs, wherein:
~ .
~ I
Figure 1 i8~ a parl:ially schematic -pictorial representation of a distributed data processing system which, may be utilized for enhanced data transmis~ion within a cellular telephone system in accordance with the method and system o the present invention;
I, Figure 2 is a pictorial representation of a plurality of assigned volce channels separated by adjacent buffer voice channels;
Figure 3 is a`high level block diagram of a data proces~ing sy~tem which may be utilized for enhanced data transmi~sion in accordance with the method and system of the present Invention snd , , .
Figure6 4a and 4b illu~trate alternate embodiments of data packets which may be utilized for enhanced data transmission in accordance with the method and syætem of ~he present lnvention.
DETAILED DESCRIPTION OF PR~ERRED EMBODIMENT
-With reference now to the figures and in particular with reference to ~igure 1, there i~ depicted a partially schématic pictorial repre~entation of a di~tributed data proce~sing system 10 which may be utilized for enh~ced data tran~mission within a cellular telephone system ln accordance with the method and' ~ystem of the present invention. Upon reference to the foregoing those - skilled in the art will appreciate that while distributed data processlng system 10 i~ i]]alætrated as including only two computers, typically such distributed data processing ~ystems include a large number of computers distributed over a -,wide geographic area.- As illustrated,; one of the computer~ within distributed data processing system 10 is a portable computer 12. Portable computer 12 i8 typically a battery powered computer which includes a low power display system 16 which preerably provides a display screen 18 which may be implemented utilizing a liquid crystal display (LCD~, a gas plasma display, or any other suitable technology display. Keyboard ~4 is ~lso provided which enable~ the user to acces~ and modify data stored within portable computer -12 in a manner well known in the art.
As those skill'ed in the art will appreciate it is increasingly common for computer~ such as portable computer 12 to include therein a miniature cellular telephone' transce~ver (not shown~ which is provided in con~unction with a modem. One example of a portable computer equipped with a combination modem/cellular telephone which may be utilized to implement portable computer 12 is- the International Business Machines Corporation Model No. 9075 PCradio. Those skilled in the art will appreciate that a modem is a 'device which may be utilized to convert digital data from a computer to an analog signal which may be tran~mitted via a teleco~ cations sy~tems. Additionally,`
, 209~7~0 such devices convert received analog signals from a telecommunications line to digital data which may be utilized by a computer. As i~ typical in ~uch systems" a cellular telephone transmits a radio frequency signal via Antenna 20 which may be received and relayed via multiple cellular system antenna 22. Thus, digital data within portable computer 12 may be converted into a series of analog signals and transmitted, via a cellular telephone and multiple intervening repeaters to a telephone system 24, in a manner well known to thoæe skilled in this art.
I
Analog ~ignals thus transmitted may be received by the ` telephone sy~tem and tran~mitted, via an ordinary telè~ho~e land line 26 to a computer 28 within distributed data processing system 10. While computer 28 is depicted as a personal computer, tho~e skilled in the art will appreciate that computer 28 may be implemented utilizing a workstation, terminal or mainframe computer, as de~ired.
Typically, computer 28 will also include a modem device permitting data from portable computer 12-to be transmitted to an* received by computer 28 an~ computer 28 may also be linked to portable computer 12 utilizing cellular technology, rather than telepholle land lines.
hu~, as those skil]ed ill the art will appreciate upon reference to the foregoing, the transmi~sion of data from portable computer 12 to comp~lter 28 utilizing depicted cellular telephone 'technology is well known in the art.
However, as the d~l4n~ on ce].lular telephone ~ystems ~, $ncrea~e and the amount of data being transmitted utilizing computers of the type depicted within Figure 1 increases, the ~- ~n~ on the available channels within a cellular telepho~e system become much greater. Thus, it should be apparent that a need exists for a method and ~ystem whereby data may be transmitted via a cellular telephone system in, an e~Anced mode without degrading the ability of the cellular telephone system to accommodate voice transml~ion~.
, Referring now to Figure 2, there is depicted a pictorial representation of a plurality of assigned voice .
BC9-92-07~ 7 {
..
chAnnels separated by adjacent buffer voice channels in a manner typically provided within a cellular telephone system. As depicted, assigned volce channels 42, 4~, ~6, 48, 50, and 52 are pictorially illustrated within a frequency spectrum and are separated, as depicted, by ad~acent buffer voice channels 54, 56, S8, 60, and-62. This i8 typically accompli~hed in order to minimize the interf~rence between two assigned voice channels which are transmitting or receiving multiple cellular telephone tran~mi~sions simultaneousl.y. Thus, by providing adjacent buffer voice c~Annel~ between ad~acent assigned voice c~A~ls, the amount of "cross talk" or other types of interference present within assigned voice channel~ may be effectively minimized.
As discussed above, it has been proposed to util$ze these adjacent buffer voice channels within the cellular telephone system for transmission of data by utilizing a low data rate, low power data transmission system; however, such systems are not effective in that the interference with ad~acent assi.gned voice channels is fairly great when the power or data rate withi.n an associated data tran~mission channel exceeds a preselected minimum. Thus, it should be apparent that a need exists for a method and ~ystem which will permit the e~lha~-ced transmis~ion of data within a cellular telephone sy~.em utilizing these adjacent bufer voice channels.
-.
The -method and system of the present inYention yields much greater data speeds and minimal interference with assigned voice channels within a cellular telephone system by implementing a "spread ~pectrum" data tran~ceiver within multiple adjacent buffer voice channels. That is, a data stream i~ divided into relatively short data packets which are se~uentially transmitted via alternate adjacent buffer voice channe}s in a predetermined -and repetitive order. Thus, the presence of data within an adjacent buffer voice channel is minimized for a particular as~igned voice, ch~nnel and the effect of interference caused by transmission of that data i.9 effectively minimized.
Additlonally, the energy density wit.hin each adjacent buffer 209~710 ~'. ' voice channel is restrained to fairly insignificant levels.
Thi~ may -be accomplished by utilizing a data processing sy~tem implemented in accordance with the method and sys~em of the present invention. A hi~h level block diagram of such a data processing system is depicted within Figure 3.
As illustrated, Figure 3 depicts~ a processor 66 which i~ utilized to control ~ynthesiæer 68. Synthesizer 68 controlo the transmit and receive frequenciés o~ transmitter 70 and receiver 72 in accordance with E IA/TIA 553 Cellular Telephone Standards. ~ata from proceRsor 66 which is to be tran~mitted by tran~mitter 70 is coupled to transmitter 70 and tran~mitted in relatively short data packets within alternating adjacent buffer voice channels in the manner de~cribed above. The output of ~transmitter 70 i8 coupled, via duplexer 74, to antenna 20 for transmission within the cellular telephsne system. -,`
Similarly, relatively short data packets may be received via antenna 20 and duplexer 74 and coupled to receiver 72. Recei'ver 72 is preferably selectively tuned to a ~erle- of predetermined adj'acent b~1ffer voice channels to receive each sequential data pac1cet and that data is coupled from receiver 72 to proceæsor h6. In this manner, a data stream may be transmitted and/or received within a cellular telephone system by dividing that data stream into a plurallty of relatively short data packets and sequentially tran#mittlng and receiving those data' packèts within àlternate adjacent buffer voice channel~ which are present between asslgned voice ~hannel~' throughout a standard cellular telephone system.
Referring now to Figures 4a and 4b, there are illu~trated two alternate embodiments of data packets which may be utilized for synchronization in the enhanced data packet transmls~ion system of the present invention. As depicted in Figure 4a, a data frame 80 is illustrated which includes a synchronization packet 82 and a data packet 84.
The length of data packet 84 is preferably fixed; however, this length may be set by the system operator. The length of data packet 84 is chosen to minimize -the amount of .
, . BC9-92-074 9 ~. I
- interference within an adjacent assigned voice channel.
Data packet 84 is preferably relatively short; however, data`
packet 84 is substantially longer than ~ynchronizat~on packet ~2.
- , - - When utilizing the data frame 80 as depicted in Figure 4a, data packet~ are preferably transmitted utilizing multipl- adjacent buffer voice chamlels in a predetermined and repet$tive order throughout all available adjacent buffer voice channels. Thus, a remote terminal may tune to a particu}ar adjacent buffer voi.ce channel and await the reception of a data packet. Thereafter, the remote terminal may tune to ~ub~equent adjacent b~tffer voice channel~ in the predetermined and repetitive order necessary to receive the data stream.
An alternate data packet format is depicted at Figure 4b wherein data frame 88 includes a synchronization packet 90, a "next channel" packet 92 and a data packet 94.
In a m~nner similar to that described above, this data packet may be utilized to tran~mit data within a cellular telephone ~ystem while minimizing interference in adjacent assigned voice channel~ without lequiri.llg a predetermined - and repetitive utilization of adjacent buffer voice ch~n~el~. By utl}izing "next channel" packet 92 to indicate the ad~acent buffer voice chantlel within which t he ~ubsequent data packet will be contained the remote terminal receiving such a data packet may rapidly and efficiently tune to the next appropriate adjacellt buffer voice channel.
Upon reference to the foregoing those skilled in the art will appreciate that by dividing a data stream into relatively short data packets and ~equentially transmitting tho~e data packets utilizing multiple adjacent buffer voice ch~nnel8 within a standard cellular telephone sy~tem, the amount of interference within an assigned voice channel may be min$mized while maintaining relatively high data rates and signal strengths.
While the invention has been particularly shown and descrlbed wlth reference to a preferred embod1ment, it ,.
.
20so7lo . BC9-92-074 10 will be understood by thos~ ~kiIled in the art that various c~ngeo in form and detail may be made therein without departlng from the ~plrlt and ^cope of the Invontlon.
`
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Claims (11)
1. A method for enhanced data stream transmission within a cellular telephone system having a plurality of assigned voice channels separated by adjacent buffer voice channels, said method comprising the steps of:
dividing a data stream into a plurality of relatively short data packets; and sequentially transmitting individual ones of said plurality of relatively short data packets within alternate ones of said adjacent buffer voice channels throughout said cellular telephone system.
dividing a data stream into a plurality of relatively short data packets; and sequentially transmitting individual ones of said plurality of relatively short data packets within alternate ones of said adjacent buffer voice channels throughout said cellular telephone system.
2. The method for enhanced data stream transmission within a cellular telephone system according to Claim 1, further including the step of concatenating a synchronization packet with each of said plurality of relatively short data packets.
3. The method for enhanced data stream transmission within a cellular telephone system according to Claim 1, further including the step of concatenating an identification of an adjacent buffer voice channel containing a subsequent one of said plurality of relatively short data packets with each of said plurality of relatively short data packets.
4. The method for enhanced data stream transmission within a cellular telephone system according to Claim 1, wherein said step of sequentially transmitting individual ones of said plurality of relatively short data packets within alternate ones of said adjacent buffer voice channels comprises the step of sequentially transmitting individual ones of said plurality of relatively short data packets within alternate ones of said adjacent buffer voice channels in a predetermined and repetitive order throughout said cellular telephone system.
5. A data processing system for data stream transmission within a cellular telephone system having a plurality of assigned voice channels separated by adjacent buffer voice channels, said data processing system comprising:
processor means for dividing a data stream into a plurality of relatively short data packets; and controllable transmitter means coupled to said processor means for sequentially transmitting individual ones of said plurality of relatively short data packets within alternate ones of said adjacent buffer voice channels throughout said cellular telephone system.
processor means for dividing a data stream into a plurality of relatively short data packets; and controllable transmitter means coupled to said processor means for sequentially transmitting individual ones of said plurality of relatively short data packets within alternate ones of said adjacent buffer voice channels throughout said cellular telephone system.
6. The data processing system for data stream transmission within a cellular telephone system according to Claim 5, wherein said processor means further includes means for concatenating a synchronization packet with each of said plurality of relatively short data packets.
7. The data processing system for data stream transmission within a cellular telephone system according to Claim 5, wherein said processor means further includes means for concatenating an identification of an adjacent buffer voice channel containing a subsequent one of said plurality of relatively short data packets with each of said plurality of relatively short data packets.
8. The data processing system for data stream transmission within a cellular telephone system according to Claim 5, wherein said controllable transmitter means coupled to said processor means for sequentially transmitting individual ones of said plurality of relatively short data packets within alternate ones of said adjacent buffer voice channels in a predetermined and repetitive order throughout said cellular telephone system.
9. The data processing system for data stream transmission within a cellular telephone system according to Claim 5, further including controllable receiver means coupled to said processor means for sequentially receiving individual ones of a second plurality of relatively short data packets within alternate ones of said adjacent buffer voice channels throughout said cellular telephone system.
10. The data processing system for data stream transmission within a cellular telephone system according to Claim 5, wherein said processor means comprises a portable battery powered data processing terminal.
11. The data processing system for data stream transmission within a cellular telephone system according to Claim 10, wherein said controllable transmitter means and said controllable receiver means comprise a cellular telephone transceiver coupled to said portable battery powered data processing terminal.
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US07/887,441 US5260989A (en) | 1992-05-21 | 1992-05-21 | Method and system for enhanced data transmission in a cellular telephone system |
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CN1080445A (en) | 1994-01-05 |
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US5260989A (en) | 1993-11-09 |
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