Difference between revisions of "Packet Radio Network"

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The '''Packet Radio Network''' was a program set up by [[DARPA]] in 1973 to explore the possibility of an ad-hoc [[data network]] using wireless links. It was perhaps most important as one of several [[physical network]] technologies being explored by DARPA, the need to interconnect which caused DARPA to work on [[internetwork]]ing, which led to the development of the [[TCP/IP]] [[protocol family]], used in today's [[Internet]].
 
The '''Packet Radio Network''' was a program set up by [[DARPA]] in 1973 to explore the possibility of an ad-hoc [[data network]] using wireless links. It was perhaps most important as one of several [[physical network]] technologies being explored by DARPA, the need to interconnect which caused DARPA to work on [[internetwork]]ing, which led to the development of the [[TCP/IP]] [[protocol family]], used in today's [[Internet]].
  
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The network included 'Packet Radio Units' (PRUs), which included all the actual radio [[electronic]]s, along with a [[microprocessor]] to implement the [[protocol]] used  for controlling the transmission of [[packet]]s between PRUs. These are connected via radio in an ad-hoc network, structured as a [[tree]] (in connectivity terms, ''not'' geography) based on a special node, the 'station', which is responsible for overall monitoring and control of the network (PRNET).
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The network included 'Packet Radio Units' (PRUs), which included all the actual radio [[electronic]]s, along with a [[microprocessor]] to implement the [[protocol]] used  for controlling the transmission of [[packet]]s between PRUs. These are connected via radio in an ad-hoc network, structured as a [[tree]] (in connectivity terms, ''not'' geography) based on a special node, the 'station' (in the prototype, a [[PDP-11/40]] running [[ELF operating system|ELF]], connected to a PRU), which is responsible for overall monitoring and control of the network (called PRNET).
  
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[[Host]]s connected to PRUs by use of an [[1822 interface]], as used to connect to [[ARPANET]] [[Interface Message Processor|IMP]]s ([[HDLC]] was much later substituted for 1822 as the physical channel for talking to the later version of the PRUs). However, rather than the [[Host-to-IMP Protocol]] used by the IMPs, PRUs used an alternative, the 'Channel Access Protocol' (CAP), which also includes some of the control mechanisms of the PRNET. CAP packets held up to 116 16-bit [[word]]s of [[user]] data, and an 11 word CAP header. On top of CAP, which is hop-by-hop, there was another layer, the 'Station to PRU Protocol' (SPP), which operated between the PRUs which were the overall source and destination of a given packet.
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[[Host]]s connected to PRUs by use of an [[1822 interface]], as used to connect to [[ARPANET]] [[Interface Message Processor|IMP]]s. ([[HDLC]] was much later substituted for 1822 as the physical channel for talking to the later version of the PRUs.)
  
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Major participants included [[Bolt, Beranek, and Newman|BBN]], which produced the [[router|gateways]] to connect the PRNET to other networks; [[SRI International|SRI]], which created the [[Terminal Interface Unit‎]] as a test user host for the PRNET; and Rockwell International's Collins division, which was responsible for the Packet Radio Units.
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However, rather than the [[Host-to-IMP Protocol]] used by the IMPs, PRUs used an alternative, the 'Channel Access Protocol' (CAP), which also includes some of the control mechanisms of the PRNET. CAP packets held up to 116 16-bit [[word]]s of [[user]] data, and an 11 word CAP header. CAP, at a high level, operates between the overall source and destination of a given packet, built on top of hop-by-hop operation. On top of CAP, there was another layer, the 'Station to PRU Protocol' (SPP), which operated between PRUs and the station, for high-level overall network control functions.
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Major participants included [[Bolt, Beranek, and Newman|BBN]], which produced the station, and the [[router|gateways]] to connect the PRNET to other networks; [[SRI International|SRI]], which created the [[Terminal Interface Unit‎]] as a test user host for the PRNET; and Rockwell International's Collins division, which was responsible for the Packet Radio Units.
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==See also==
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* [[Terminal Interface Unit]]
  
 
==Further reading==
 
==Further reading==
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* [https://en.wikipedia.org/wiki/PRNET PRNET]
 
* [https://en.wikipedia.org/wiki/PRNET PRNET]
 
* [https://www.rfc-editor.org/ien/ien78.pdf Internetwork Experiments with the Bay Area Packet Radio Network]
 
* [https://www.rfc-editor.org/ien/ien78.pdf Internetwork Experiments with the Bay Area Packet Radio Network]
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* [https://www.rfc-editor.org/ien/ien138.pdf Initial Comparison of EPRs and IPRs in the Pup Internet Environment]
 
* [http://ana-3.lcs.mit.edu/~jnc/tech/mos/dsp/ DSP] - source code (in [[MACRO-11]]) for SPP in the [[Terminal Interface Unit‎]]
 
* [http://ana-3.lcs.mit.edu/~jnc/tech/mos/dsp/ DSP] - source code (in [[MACRO-11]]) for SPP in the [[Terminal Interface Unit‎]]
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* [https://www.computerhistory.org/collections/catalog/X1590.99 SRI Mobile Van] - a key element of the first packet radio network
  
 
[[Category: Networking]]
 
[[Category: Networking]]

Latest revision as of 19:49, 29 January 2024

The Packet Radio Network was a program set up by DARPA in 1973 to explore the possibility of an ad-hoc data network using wireless links. It was perhaps most important as one of several physical network technologies being explored by DARPA, the need to interconnect which caused DARPA to work on internetworking, which led to the development of the TCP/IP protocol family, used in today's Internet.

The network included 'Packet Radio Units' (PRUs), which included all the actual radio electronics, along with a microprocessor to implement the protocol used for controlling the transmission of packets between PRUs. These are connected via radio in an ad-hoc network, structured as a tree (in connectivity terms, not geography) based on a special node, the 'station' (in the prototype, a PDP-11/40 running ELF, connected to a PRU), which is responsible for overall monitoring and control of the network (called PRNET).

Hosts connected to PRUs by use of an 1822 interface, as used to connect to ARPANET IMPs. (HDLC was much later substituted for 1822 as the physical channel for talking to the later version of the PRUs.)

However, rather than the Host-to-IMP Protocol used by the IMPs, PRUs used an alternative, the 'Channel Access Protocol' (CAP), which also includes some of the control mechanisms of the PRNET. CAP packets held up to 116 16-bit words of user data, and an 11 word CAP header. CAP, at a high level, operates between the overall source and destination of a given packet, built on top of hop-by-hop operation. On top of CAP, there was another layer, the 'Station to PRU Protocol' (SPP), which operated between PRUs and the station, for high-level overall network control functions.

Major participants included BBN, which produced the station, and the gateways to connect the PRNET to other networks; SRI, which created the Terminal Interface Unit‎ as a test user host for the PRNET; and Rockwell International's Collins division, which was responsible for the Packet Radio Units.

See also

Further reading

  • Robert E. Kahn, Steven A. Gronemeyer, Jerry Burchfiel, Ronald C. Kunzelman, Advances in Packet Radio Technology, Proceedings of the IEEE (Volume: 66, Issue: 11, Nov. 1978), pp. 1468-1496 (online precis available here)
  • M. Beeler, SPP Definition, PRTN No. 177, ARPA Packet Radio Network working document, April 1976

External links

Retrieved from "https://gunkies.org/w/index.php?title=Packet_Radio_Network&oldid=33115"