دانلود رایگان مقاله TRM-MAC: پروتکل چندپخشی مبتنی بر TDMA MAC برای شبکه گیرنده بی سیم

Abstract

Multicast in wireless sensor networks (WSNs) is an efficient way to deliver the same data to multiple sensor nodes. Reliable multicast in WSNs is desirable for critical tasks like code updation and query based data collection. The erroneous nature of the wireless medium coupled with limited resources of sensor nodes, makes the design of reliable multicast protocol a challenging task. In this paper, we propose a framework for reliable multicast transmission in WSNs using TDMA-based channel access which works on top of a Multicast Spanning Tree (MST) rooted at the base station. The existing TDMA-based MAC protocols do not provide any mechanism to handle the collision and explosion of feedback messages, and therefore, they cannot be used in the proposed framework to support reliable multicast. To handle this issue, we propose a TDMA-based reliable multicast MAC (TRM-MAC) protocol for WSNs. The TRM-MAC protocol is parametric in the sense that it can be used to trade-off between reliability and delay performance, as per the requirement of the underlying applications. We have analyzed the TRM-MAC protocol to evaluate its delay and reliability performance at different packet loss rates, and have also compared its performance with those of others using simulation study. Both simulation and analytical results show that the TRM-MAC protocol considerably improves the performance of multicast communication in WSNs.

8. Conclusions

In this work, we have suggested a framework for reliable multicast transmission in WSNs and proposed a TDMA-based MAC protocol with hybrid link layer and retransmission scheme within this framework. One of the unique feature of TRM-MAC protocol is its ability to trade-off reliability with delay and energy as per the requirement of applications and channel conditions using maxRetries and nACK parameters. The simulations and analytical results show that the TRM-MAC protocol is able to considerably improve the reliability performance of multicast communication in WSNs while ensuring reasonably low access delay at the same time. Additionally, a high degree of reliability can be achieved, if a WSN uses TRM-MAC protocol along with an end-to-end reliable multicast solution at link layer and transport layer respectively by appropriately partitioning the task of reliability at both these layers.