Abstract
Considered to be one of the most important aspects in the personal communications, different service types of traffic should be supported by the cellular mobile radio networks. These types could be voice calls, data packets, ..etc. These types differ from each other in their requirements of accepted performance. While a voice call should not be disconnected, it is not a problem to retransmit a data packet after having a transmission failure.
Queueing and prioritization for these different types, when the system reaches the congestion point, is essential to improve the system performance for each type of traffic. Also, prioritization can be applied among the users of one type, like giving the priority for ambulance and military calls over ordinary calls.
One of the proposed prioritization algorithms in the literature is studied and two mathematical modifications are introduced. The first one concerns the equation that calculates the failure probability for getting a service. The second is considering the mobility of the user after ceasing a channel and being served. Having resolved the system mathematically and run the simulation, the results obtained from these two different techniques are in a complete matching to each other, while they differ from those obtained before considering the modifications.
As a conclusion, the mobility of users is a very important parameter which considerably affects the system performance and cannot be neglected. Also, OPNET is a very powerful and reliable simulation environment which should be considered as a simulation tool in the next researches.
Author’s original abstract, transcribed from the thesis; line wrapping normalised.
Research overview
Analyzing channel assignment under unequal service priorities.
The thesis studies cellular systems in which user classes can have different channel-assignment priorities. It develops analytical models and simulation experiments to examine service failure probability and the effects of subscriber movement after a channel has been assigned.
The work compares mathematical results with OPNET simulations and shows why mobility must be considered when evaluating prioritized assignment policies.
Suggested citation: Yousef, Waleed Ahmed. “Simulation of Prioritized Channel Assignment Models in Cellular Mobile Radio Networks.” M.Sc. thesis, Helwan University, 1999.