A multi-channel multiple access scheme using frequency offsets — Modelling and analysis

Abstract

Abstract-A system using frequency offset based transmitreference (TR) modulation allows multiple nodes to transmit simultaneously and asynchronously without any mutual timing coordination. Thus, such a system provides inherent capabilities for a multiple access in the medium access control (MAC) layer to coordinate the shared use of the common wireless medium among the nodes of the wireless sensor network (WSN). However, certain characteristics of a frequency offset based system limits its performance, for example, the number of available frequency offsets is limited as it depends on several system parameters, and the number of simultaneous communications using different frequency offsets is limited due to inter-user interference. In this paper, we introduce an extended version of the performance model of a basic slottedAloha system, that captures the basic phenomena of a multichannel system with a limited set of channels and a limit to the number of simultaneously used channels. An analysis of this model reveals the potential of a MAC protocol for TR modulation with frequency offsets.

Energy-efficient Medium Access Control for Transmit Reference Modulation

“…Hence, in this chapter we model the effects of frequency offset based TR modulation as a basic multiple access technique to analyze the potential benefits as well as to understand the consequences of the limiting factors at the upper MAC layer. The content of this chapter is based on the publication [23].…”

“…This chapter answers research question 4 ("How do the multi-channel properties affect the performance of multiple access control in a system using transmit reference modulation with frequency offsets?"). In this chapter, we propose and analyze a model for a multiple access scheme using frequency offsets, which is based on our published paper [23]. As our starting point, we take a basic model of single channel slotted Aloha (S-Aloha) [73].…”

“…Hence, a medium access control for a frequency offset based system is needed in the MAC layer. Earlier in Chapter 5, we proposed a multiple access model for multi-channel medium access control using frequency offsets, and analyzed its performance potential at the MAC layer based on the publication [23]. In this chapter, we extend the energy-efficient medium access control TR-MAC protocol, introduced in Chapter 3, based on the publications [19,20,21], for the multiple access control with frequency offset based transmit reference modulation, and analyze its performance in a wireless sensor network with multiple access scenario.…”