Window Random Access Algorithm Research Articles

Packet reservation window multiple access for microcellular voice/data transmission

We propose a new packet reservation multiple access (PRMA) scheme for the joint transmission of voice and data traffics in a microcellular medium. The collision resolution protocol within the system is based on a modification of the window random access algorithm, which has superior properties compared to the conventional slotted Aloha. The proposed algorithm, which we call packet reservation window multiple access (PRWMA), works in distinct modes for voice and data without prioritization, and the user performs slightly different operations depending on the information type. Simulation results show that PRWMA outperforms PRMA by a significant margin in terms of voice user capacity.

Mobile radio window random-access algorithm with diversity

We consider a mobile radio random-access algorithm equipped with a choice of three distinct antenna diversity plans (two-fold, maximum selection, or ideal selection diversity) to improve the performance. The algorithm is stable with high throughput and low delays. The mobile environment is regulated by the presence of multipath fading, shadowing, and path loss. The capture model is a threshold model based on the signal-to-interference ratio. The maximum throughput and optimal window size of the algorithm are analytically computed. The delay performance is evaluated through simulations, and significant improvement is demonstrated over slotted ALOHA under various mobile scenarios.

Letter Throughput and Delay Analysis of the Ideal Window

AbstractWe consider the problem of random access communications over a time slotted channel with feedback of infinitely multiplicity at the beginning of each collision resolution interval (CRI), i.e., users know via instantaneous feedback the number of users involved in that collision. Once this is known, the resolution algorithm (CRA) operates with binary (successful / non successful, s/ns) feedback. The analysis of this simple full feedback sensing window random access algorithm, named ideal window stabilized ALOHA, (IWSA), algorithm, provides a throughput of 0.5052 packets/slot. Its delay is also analyzed and compared with similar algorithms.

Bounds on the delay distribution of window random-access algorithms

A method for analyzing the delay distribution of window random-access algorithms is presented. The window size is allowed to vary during the operation of the algorithm. It is shown that the quantities of interest in the computation of the delay distribution can be related to the solution of appropriate infinite systems of linear equations. Once the constants and the coefficients of the unknowns of the system are determined, bounds on the solution can be developed by applying previously developed methodologies. The method is applied to the delay distribution analysis of the Capetanakis window random-access algorithm and the part-and-try algorithm, both under binary feedback. >

A window random access algorithm for environments with capture

The authors propose and analyze a stable random access algorithm which is a modification of the two-cell algorithm proposed by M. Paterakis (1984). The authors assume ternary feedback broadcast per slot, and in the presence of capture, identification of the captured packet by all the users in the system. It is also assumed that a successfully received signal transmission cannot be distinguished from a capture in the presence of multiple transmission. The performance of the algorithm is compared to an appropriate modification of J.I Capetanakis' (1979) dynamic algorithm. The proposed algorithm, and in contrast to the latter, it can be easily modified to operate in limited feedback sensing environments.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

A full sensing window Random-Access algorithm for messages with strict delay constraints

We consider the Channel Multiple-Access problem for messages with strict delay constraints. The constraints are represented by an upper bound on the transmission delays. For this problem, and for binary collision-noncollision feedback per slot, we present a simple full sensing window Random-Access algorithm. We analyze the algorithm and we compute the fraction of maintained traffic and the expected delay for the successfully transmitted packet, for various input Poisson intensities and various values of the bound on the transmission delays.

A simple window random access algorithm with advantageous properties

A simple full-feedback-sensing window random access algorithm is proposed and analyzed. The throughput of the algorithm is 0.429; its delay and resistance to feedback channel errors are better than those induced by J.I. Capetanakis's (ibid., vol.IT-25, p.505-15, Sept. 1979) window algorithm. In addition, the simple operations of the algorithm allow for the analytical evaluation of the output-traffic interdeparture distribution. >