Non-persistent CSMA Protocol Research Articles

Modeling the slotted nonpersistent CSMA protocol for wireless access networks with multiple packet reception

In this paper, we propose probability models for performance analysis of the slotted nonpersistent CSMA protocol in wireless networks with multiple packet reception. Variants of the CSMA protocol are well-known and play important roles in medium access control. Most of the previous works on CSMA use the conventional (0, 1, e) channel model, which prohibits an access point from concurrently receiving multiple packets from distinct nodes. In this paper, we use the Poisson random traffic model to study the performance of the slotted nonpersistent CSMA protocol when the access point could simultaneously receive two or more packets from different nodes in wireless access networks. We show that in terms of the network throughput, our analytical results are consistent with simulation results.

Performance analysis of CSMA and BTMA protocols in multihop networks (I). Single channel case

Busy tone multiple access protocols have been used in multihop networks to reduce the effect of the hidden terminal problem. Due to complexity, the performance of these protocols for large networks has not been analyzed. In this paper, using a Markov chain model and an approximation, we are able to analyze and evaluate the throughput performance of the non-persistent CSMA protocol, the conservative busy tone multiple access (C-BTMA) protocol and the ideal destination-based busy tone multiple access (ID-BTMA) protocol for large networks. The throughput comparison of the protocols is given. The results show that in a large multihop network, the BTMA protocols have a better performance than the non-persistent CSMA protocol and the ID-BTMA protocol has a better performance than the C-BTMA protocol at light channel loads.

Stability and throughput optimization of multichannel slotted non-persistent CSMA protocol

This paper describes two protocols suitable for a multichannel, multiaccess slotted non-persistent CSMA environment for infinite population, analyses their stability and examines their throughput optimization. The common sensing multichannel slotted non-persistent CSMA (CSCSMA) protocol is an extension of the slotted single channel non-persistent CSMA protocol with an appropriate policy for the selection of the channel in which a station (re)transmits. This policy restricts the control information among the stations, and consequently reduces the cost of the station interface. Pakes's Lemma criteria are applied to define sufficient conditions for ergodicity of the Markov chain, which describes the evolution of the busy station population, and to specify regions in which the multichannel system is stable. Control parameters are the retransmission probabilities. Optimization rules are derived which show that the optimal retransmission probabilities may be expressed as a function of the number of busy stations. The separate sensing multichannel slotted non-persistent CSMA protocol (SSCSMA), using a different policy, distinguishes the channels into two groups: the retransmission channel group devoted in collision resolution; and the transmission channel group for the access of free stations. Stability regions are defined using the results for CSCSMA, and rules for optimal allocation of channels among the two groups are derived for improvement of system performance.

Stability and throughput optimisation of multichannelslotted nonpersistent CSMA random choice protocol

The analysis of stability and throughput optimisation of a multichannel multiaccess slotted nonpersistent CSMA random choice protocol for infinite population is examined. The proposed protocol is an extension of the slotted single channel nonpersistent CSMA protocol with random selection policy of the channel in which a station (re)transmits. Optimisation rules are derived which show that the optimal retransmission probabilities may be expressed as a function of the number of busy stations. Stability regions are also specified.

Analysis of the semisynchronous carrier sense multiple access on the bus topology

Consider an arbitrary number of stations equally spaced on a channel configured as a bus topology. The stations access the channel according to the nonpersistent CSMA protocol, which may be with or without collision detection. Users are synchronized to the propagation delay between two adjacent users, and are thus semisynchronized. Such a system with single-buffered users and an exponential backoff strategy, is modeled. The system throughput and the mean delay are evaluated, and it is shown how to obtain the distribution of the packet interdeparture time as well as the packet delay. It is shown that the rescheduling strategy has a profound effect on the station performance, and that it can be used to eliminate the difference between the performance of different stations at any given offered load. The model is also used to accommodate finer synchronization steps, as well as arbitrary topologies. >