Assigning service requests in Voice-over-Internet gateway multiprocessors

New and proposed communication systems are entirely digital, including Voice over Internet Protocol tasks as well as traditional data packets, fax, etc. Numerous digital signal processing (DSP) algorithms are available to encode and decode these signals, each having different requirements for data memory, program memory, and processor speed. A DSP multiprocessor having numerous DSP cores receives a stream of requests for encoding and decoding tasks. A service request is “blocked” if no DSP core can handle the task when it arrives. We present algorithms for assigning DSP tasks to cores in order to minimize the number of blocked tasks. This is similar to an online bin-packing problem with the important difference that the program memory can be shared between simultaneous service requests for the same DSP algorithm. Since bin-packing is known to be NP-complete, we develop fast heuristic online methods for this problem.