Optimal Guaranteed Services Timed Token (OGSTT) Media Access Control (MAC) Protocol for Networks That Support Hard Real-Time and Non Real-Time Traffic

In networks that support real-time traffic and non-real-time traffic over the same physical infrastructure, the challenge to the Media Access Control (MAC) protocol of such network is the ability to support  the different traffic without compromising quality of service (QoS) for any of them. Generally, timed-token MAC protocols group the diverse real-time traffic into one category and then dedicate certain portion of the available bandwidth to them. At the same time, some bandwidth are left unassigned but available to the non real-time traffic. The unassigned bandwidth, and in some cases, the unused bandwidth left by the real-time traffic are assigned to the non-real-time traffic on best effort basis. In this paper, Optimal Guaranteed Services Timed Token (OGSTT) MAC protocol is developed and analyzed. In order to provide better support for both real-time traffic and non-real-time on the same local area network, OGSTT employs the timed-token mechanisms in the Timely-Token protocol along with that of Budget Sharing Token (BuST) protocol. Some bounds on the behavior of OGSTT protocol are discussed along with the ability of OGSTT protocol to support real-time and non-real time traffic. In particular, the paper demonstrated that the performance achieved by OGSTT is better than the Timely-Token and BuST. Furthermore, OGSTT protocol can be incorporated into the Ethernet network to provide real-time performance guarantees to multimedia applications and hard and soft real-time traffic

Time Properties of the Bust Protocol Under the NPA Budget Allocation Scheme

Token passing is a channel access technique used in several communication networks. Among them, one of the most effective solution for supporting both real-time traffic (synchronous messages) and non real-time traffic (asynchronous messages), is the so-called timed-token protocol. Recently, a new token passing protocol, called Budget Sharing Token protocol (BuST), was proposed to improve the existing timed-token approaches in terms of synchronous bandwidth guarantee, while guaranteeing a minimum throughput for the asynchronous traffic. This paper analyzes the ability of BuST to manage real-time and non real-time traffic in comparison with the classic timed-token protocol and its modified version, under the Normalized Proportional Allocation (NPA) scheme. We will show that BuST achieves higher guaranteed real-time bandwidth than the original timed-token protocol, and improves the service for the non real-time traffic respect to its modified version

Design and implementation of an energy-aware protocol for multi-hop real-time communications in wireless networks

This work presents an extension of the WBuST real-time procotol for multi-hop wireless networks composed of embedded devices. These devices, usually battery powered, also requires careful managing of the power consumption in order to extend the battery life at most. This protocol organizes the network as a cluster tree and provide the routing capabilities to transfer the packets among the devices, guaranteeing the packet delivery within their deadlines. At the end of the document, an analysis of the protocol performance are presented