Physical Layer and MAC Design for Self-Reliant Cognitive Multicast Networks Using LTE Resources

Abstract

Existing Long Term Evolution (LTE) networks have untapped radio frequency resources, also known as white space, that can be repurposed for cognitive radio applications. A secondary network can opportunistically interweave communication within the white space of an existing LTE signal by leveraging cognitive radio. In this article, we present CIAO-LTE, a novel framework for forming a cognitive interwoven self-reliant secondary network with no additional physical infrastructure, collaboration from the existing primary network, and software or hardware changes in the primary LTE network. For medium access control, CIAO-LTE uses an adapted version of Slotted ALOHA with a no-back-off contention. We analyze parameter settings and conduct extensive simulations to validate performance. The simulation results show that CIAO-LTE achieves throughputs as high as 4.75 Mb/s on a 5MHz LTE signal and approximately 19Mb/s with a 20MHz LTE signal, and average packet delays within a few milliseconds.