Browse Prior Art Database

Medium-Access Protocol for Contention Based, Slotted, Multi-user Communication Networks

IP.com Disclosure Number: IPCOM000117151D
Original Publication Date: 1996-Jan-01
Included in the Prior Art Database: 2005-Mar-31
Document File: 4 page(s) / 111K

Publishing Venue

IBM

Related People

Bisdikian, C: AUTHOR

Abstract

Disclosed is a protocol for coordinating the transmission of information packets among stations on randomly accessed, shared communication media, like the ones found in wireless, mobile networks, or Hybrid Fiber-Coax (HFC) cable TV networks. System efficiency in such networks is increased by providing contention minislots to send reservations for transmissions in data payload fields. The disclosed mechanism increases the system capacity even further by allowing transmissions on both the contention minislots and data payloads depending on the network load.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Medium-Access Protocol for Contention Based, Slotted, Multi-user
Communication Networks

      Disclosed is a protocol for coordinating the transmission of
information packets among stations on randomly accessed, shared
communication media, like the ones found in wireless, mobile
networks, or Hybrid Fiber-Coax (HFC) cable TV networks.  System
efficiency in such networks is increased by providing contention
minislots to send reservations for transmissions in data payload
fields.  The disclosed mechanism increases the system capacity even
further by allowing transmissions on both the contention minislots
and data payloads depending on the network load.

      Consider a slotted transmission axis, and Fig. 1 depicts a
typical transmission slot with M=2 contention minislots and a data
payload section.  It is assumed that by the end of the slot
(although, this assumption can be relaxed), the station receives
feedback regarding its transmission in the slot.  The station also
receives information about the number P of data payloads currently
already reserved.  The count P is assumed to be provided by a monitor
station that monitors all traffic activity on the network and
notifies all station on the outcome of their transmissions.

The protocol is summarized in Fig. 2.  There are three transmission
phases:
  1.  If a newly activated station finds P=0, it attempts
transmission
       directly at the payload field.  If the transmission in
successful
       the newcomer is "done."
  2.  If the previous transmission was a collision or a newly
activated
       station finds P ge 1, then the station chooses a contention
       minislot and transmits in it.  The station utilizes a
collision
       resolution algorithm to resolve possible collisions in the
       contention minislot.
  3.  When the collision in a contention minislot is resolved the
       station is scheduled for a future payload transmission based
on
       the information provided by the P count.

Let S denote the number of successful transmissions in the minislots
of a slot.  Then, if at the end of a slot the count P
  o  equals 0, then, P larrow S;
  o  is larger than 0, then, P larrow P - 1 + S .

The "-1"  above comes from the transmission of one data payload due
to a successful minislot transmission at an earlier time.

      A number of collision resolution algorithms could be used
in transmission phase 2 above.  We choose to use the n-ary Stack
Algorithm (nSA),(*), because of its limited feedback sensing
property and stable throughp...