A Parallel Software Architecture for the LTE Protocol on a Multi-Core Mobile Modem

Abstract

Coming wireless communication standards like Long Term Evolution (LTE) promise to bring a drastic increase in data rate for the end user. To facilitate this evolution, sophisticated technology for the mobile equipment is required. Most research focuses on the signal processing in the physical layer whereas the computational capabilities for protocol processing are neglected. This paper describes novel software architecture and load balancing for the LTE protocol stack that allows concurrent execution on a multi-core processor and thus allows for exploiting all the advantages like higher performance through parallelism at low power consumption. The layered protocol is developed using Specification and Description Language (SDL). In addition, the LTE protocol stack is parallelized and executed on a multi-core processor, by employing the SDL processes concurrency. Moreover, the LTE system is scheduled on multi-core by customizing the SDL scheduler to implement a data pipeline scheduler. Furthermore, a new load balancer scheme is proposed by moving the load balancer to the modem subsystem’s layer and using the SDL process migration concept. The performance of the LTE protocol implementation using the new scheme beats the classic thread migration scheme by more than 50% on single as well as multi-core platforms. The data throughput using the new scheme increases on two, three, or four cores, compared to single core, by about 195%, 290%, and 360%, respectively, and thus shows an excellent scalability for up to three cores and still giving reasonably good results for four cores.