Impact of mobile-originated short message service on the digital control channel of TDMA systems

This paper evaluates the capacity of the ANSI-136 digital control channel (DCCH) uplink to carry high volumes of mobile-originated short message service (MO-SMS) traffic. The DCCH random access protocol is characterized and it is found that a random access channel (RACH) parameter setting of (10,3,4,2) is optimum for providing good RACH performance. Simulation results indicate that the RACH has sufficient capacity to handle moderate levels of MO-SMS traffic. For cells with moderate and high levels of voice call traffic, it is found that the RACH can handle a MO-SMS traffic load of up to 1000 MO-SIMS messages per hour without significantly affecting the performance of critical messages such as originations and page responses. It is found that when MO-SMS traffic levels exceed 1000 messages per hour, blocking rates of critical messages such as originations and page responses start rising, potentially affecting the quality of service experienced by the wireless customer