On the WiMAX and HSDPA Coexistence

Abstract

In this work we develop Markovian models to study the dynamics of elastic calls in a cell served by HSDPA and WiMAX systems. We first present analytical models for interference and throughputs in WiMAX and HSDPA. We then consider two different strategies of Joint Radio Resource Management (JRRM) with or without inter-system vertical handovers and show how to calculate the steady-state probabilities and the performance measures (blocking probabilities, mean sojourn times, loads). Our numerical results compare the different JRRM strategies and point out the advantages and drawbacks of each of them. We find out that, although JRRM with vertical handover achieves the best performance, the throughput maximising strategy without inter-system handovers has an acceptable performance and may be adopted in the first cooperative networks until constructors' handover solutions become more mature.

Joint Radio Resource Management for HSDPA and WiMAX Networks

“…The vector π 0 is then determined by solving the boundary equation: This section, presents a comparison between the proposed cooperative JRRM protocol and the previously published results in [3]. Hence, a comparison between the proposed cooperative JRRM protocol and the individual networks will be illustrated.…”

“…Fig. 2 shows a performance comparison between the proposed JRRM protocol and the results published in [3]. As illustrated before, the proposed JRRM protocol aims to utilize the network resources at small and moderate network loads, these lead to avoid rapid network congestion and increase the overall system efficiency.…”

“…In the suggested scheduling algorithm, instead of dividing the entire BW into subchannels, which is assigned to each user upon his arrival as in [3], the base station gives the first user the entire BW, and upon the arrival of a new user the BW is equally shared between all the served users. After reaching the maximum capacity of M W , any new request will be directed to the other network or will be blocked.…”

“…As illustrated before, the proposed JRRM protocol aims to utilize the network resources at small and moderate network loads, these lead to avoid rapid network congestion and increase the overall system efficiency. In [3] upon the arrival of each user, the call admission controller allocates the user a variable portion of the available spectrum depending on the number of served users. So there is a portion of the resources will not be utilized at small and moderate network loads, which leads to rapid network congestion.…”

“…The network selection algorithm may be based on the user application constrains, mobility profile and operator policies. In [3], a network selection algorithm was analytically developed based on throughput maximization for HSDPA and WiMAX cooperation. Whereas in [4], the developed algorithm was based on user preferences and service application for WLAN and UMTS cooperation.…”