Abstract

A hybrid of TDMA and CDMA or the so-called time slotted CDMA is a popular mainstream multiple access technique in coordinating resource to accommodate a number of traffic connections/sources. The purpose of this paper is to conduct thorough delay analysis for a specific connection in such a hybrid TDMA/CDMA MAC protocol. The arrival process of this connection is assumed to be the Markov modulated Poisson process (MMPP) and can be generalized to the batch Markov arrival process (BMAP). The service that can be rendered to this connection in time and code is made general to fit any service pattern that one may configure. Past works on the delay analysis of a TDMA system are special cases of this paper. The results obtained in this paper can be used to evaluate the performance of many contemporary quality of service (QoS) oriented frame-based MAC protocols. (A website (http://pages.stern.nyu.edu/ychen0/Delayanalysis.htm) providing an environment so that interested readers may access to use the results derived in this paper is currently available.)

Author Keywords: Author Keywords: Delay analysis; Frame-based MAC protocol; TDMA; CDMA

Article Outline

1. Introduction

2. Preparation

2.1. The hybrid TDMA/CDMA protocol

2.2. The traffic source

2.2.1. MMPP

2.3. Notation

3. State transition matrix

3.1. X_n≥1

3.2. X_n=0

3.2.1. a_p+1≤a_q−1

3.2.2. a_p+1>a_q−1

4. System size distribution at an arbitrary time

4.1. t[a_q−1,a_q)

4.2. t[a_q−1,a_q−1)

5. Sojourn time distribution

5.1. Preparation

5.2. Virtual sojourn time

5.2.1. t[a_q−1,a_q−1)

5.2.2. t[a_q−1,a_q)

5.3. Actual sojourn time and its moments

5.3.1. First moment

5.3.2. Second moment

5.4. Complexity analysis

5.5. A remark

6. Two special cases

6.1. A TDMA system with Poisson arrivals

6.2. A pure CDMA system with Poisson arrivals

7. Numerical examples and discussions

8. Conclusions

Acknowledgements

References

Vitae

Corresponding author.

*1 This work was performed when the authors were with Graduate Institute of Communication Engineering, National Taiwan University, Taipei 107, Taiwan, ROC.