Energy consumption of the IEEE Std 802.15.3 MAC protocol in communication link set-up over UWB radio technology

This paper examines the overhead associated with the IEEE Std 802.15.3 medium access control (MAC) protocol when used in conjunction with Ultra Wide-Band (UWB) radio technology. Particular features of the protocol examined include establishing, modifying and terminating data streams. The main focus of the paper is to investigate the overhead introduced in terms of energy consumption to manage the communication links. One of the main UWB technology candidates, Impulse-Radio (IR-UWB), utilizes very short time domain pulses which are low power and difficult to detect. This raises the question of how to design an efficient MAC protocol to harness the potential of the physical layer (PHY). For high data rate WPAN applications, the IEEE Std 802.15.3 protocol has been proposed as a suitable MAC. In the simulations the data source rate and the number of devices in the network are varied and the considerable overhead produced by command frames is observed.     

Performance Analysis for a New Medium Access Control Protocol in Wireless LANs

One fundamental issue in high-speed wireless local area networks (LANs) is to develop efficient medium access control (MAC) protocols. In this paper, we focus on the performance improvement in both MAC layer and transport layer by using a novel medium access control protocol for high-speed wireless LANs deploying carrier sense multiple access/collision avoidance (CSMA/CA). We first present a recently proposed distributed contention-based MAC protocol utilizing a Fast Collision Resolution (FCR) algorithm and show that the proposed FCR algorithm provides high throughput and low latency while improving the fairness performance. The performance of the FCR algorithm is compared with that of the IEEE 802.11 MAC algorithm via extensive simulation studies on both MAC layer and transport layer. The results show that the FCR algorithm achieves a significantly higher efficiency than the IEEE 802.11 MAC and can significantly improve transport layer performance.     

A Medium Access Control Protocol for Real Time Video over High Latency Satellite Channels

We report the results of extensive simulation work on a new satellite medium access control (MAC) protocol for medium quality interactive video. This MAC protocol uses combined random access/demand assigned multiple access (RA/DAMA). The underlying multiple access physical layer is time division multiple access (TDMA). The RA/DAMA MAC seeks to adaptively minimize the delay of each network layer (nl) packet that arrives to the output queue by transmitting packets on either a collision free demand assigned channel or on a collision possible random access channel. Combined with this dual channel transmission method is a new technique for acquiring demand assigned bandwidth, called a packet flow rate metric (PFRM). This metric seeks to track the slow time behavior of video traffic, leading to a significant reduction in the amount of DAMA signaling. All simulations were conducted using SMACS, the Satellite Medium Access Control Simulator [4], a simulation tool built into ns-2.0 (network simulator version 2) [10]. This simulation tool allowed us to evaluate our MAC protocol using an actual 2 hour long video trace rather than a parametric video traffic generator. Our results show that if light packet loss is tolerable (less than 3%), then significantly lower delays and higher link utilization can be achieved.     

基于节点接入能力的ad hoc网络按需路由协议

基于802.11协议MAC层重传策略,提出一个衡量节点接入能力的参数CAM(capacity of access to medium),以体现节点周围信道的繁忙程度及其抢占信道能力。在此基础上,联合MAC层和网络层进行跨层设计,提出了一个拥塞感知路由CAOR(congestion aware on-demand routing)协议。仿真表明:该协议能够在降低开销的前提下,显著增加网络吞吐量,并降低平均端到端的时延。     

Sustainable simultaneous communications in ad-hoc networks using smart antenna systems

This article proposes an analytical model for evaluating the number of simultaneous communications that can be sustained by an ad-hoc network in which the nodes are equipped with fully adaptive smart antennas. The presented mathematical framework adopts realistic models for the antenna radiation pattern and the channel behavior, and is able to take into account the network topology and the characteristics of the medium access control (MAC) protocol in the spatial domain. The model is employed to investigate the impact of the spatial channel model and of the angular spread on network performance. Additionally, this article examines the influence of the transmission policy of the control and data packets of the MAC layer on the number of simultaneous communications.     

Saturation throughput analysis of a carrier sensing based MU-MIMO MAC protocol in a WLAN under fading and shadowing

In wireless local area networks (WLANs), the traditional carrier sense multiple access with collision avoidance (CSMA/CA) medium access control (MAC) protocol cannot use the full benefits from multiuser multiple-input multiple-output (MU-MIMO) technique due to random medium access of the users. In this paper, we propose a carrier sensing based MAC protocol for a MU-MIMO based WLAN with full utilization of MU-MIMO technique. By modeling the WLAN system under the proposed MAC protocol as a discrete time Markov chain, we develop an analytical model for computing the saturation throughput in presence of path loss, Rayleigh fading and log-normal shadowing. The analytical model is then validated via simulation. By means of numerical and simulation results, we demonstrate that the proposed MAC protocol significantly improves throughput performance than the traditional CSMA/CA MAC protocol. Further, we compare the performance of the proposed MAC protocol with a MU-MIMO MAC protocol called Uni-MUMAC protocol and find that the proposed MAC protocol performs better than the Uni-MUMAC protocol. We also explore the effect of some of the network and wireless channel parameters on the performance of the proposed MAC protocol.

     

Analytical performance of soft clustering protocols

The success of a mobile ad hoc network (MANET) is strongly related to the protocol used at the medium access control (MAC) layer. Depending on the requirements and the specific network under concern, the protocol parameters at the MAC layer can be arbitrated to make best use of the channel resources. Typically, extensive simulation studies are used to find the best values for these variables. The problem with this approach is the need for excessive amounts of processing power and time. As the dimensions of the decision space increase, the need for processing power grows exponentially. This paper addresses this problem by developing an analytical model that reflects the relationships between protocol parameters and the overall performance of the protocol under various network conditions. Specifically, we model the MH-TRACE cluster-based protocol, which is capable of supporting real-time data transmission. The model is capable of estimating performance measures such as energy consumption and number of receptions while being simple enough to be run for a large set of parameters. The model can be used to optimize parameters of the protocol (such as the number of frames per superframe) as well as to predict the performance variations as the external conditions (such as data generation rate) vary.     

Markov chain model for performance analysis of transmitter power control in contention based wireless MAC protocol

We have developed a three-state discrete-time Markov-chain model for the performance evaluation of contention-based medium access control (MAC) protocol. The proposed Markov-chain model is then used to analyze the carrier sense multiple access (CSMA) type MAC protocol for its delay and throughput characteristics with and without transmitter power control. Using simulations, the conditional capture probability (p _cap ), which gives a measure of the effectiveness of transmitter power control due to the capture effect, is quantified and experiments are performed to validate these simulated data for the p _cap . To analyze the effect of transmitter power variation, the Markov-chain model is modified by incorporating the p _cap . Numerical results show significant throughput as well as delay performance improvement using transmitter power control.     

Model-based admission control for IEEE 802.11e enhanced distributed channel access

IEEE 802.11e enhanced distributed channel access (EDCA) is a distributed medium access scheme based on carrier sense multiple access with collision avoidance (CSMA/CA) protocol. In this paper, a model-based admission control (MBAC) scheme that performs real-timely at medium access control (MAC) layer is proposed for the decision of accepting or rejecting requests for adding traffic streams to an IEEE 802.11e EDCA wireless local area network (WLAN). The admission control strategy is implemented in access point (AP), which employs collision probability and access delay measures from active flows to estimate throughput and packet delay of each traffic class by the proposed unsaturation analytical model. Simulation results prove accuracy of the proposed analytical model and effectiveness of MBAC scheme.     

FULL-RCMA: a high utilization EPON

This paper proposes an alternate solution for Ethernet passive optical networks. Our solution uses a novel protocol named full utilization local loop request contention multiple-access protocol to efficiently provide communications in passive optical networks. We study the physical layer implementation, as well as medium access control (MAC) layer protocol performance to illustrate the feasibility and benefit of our solution. The performance studies show that the MAC protocol is capable of offering 95% channel utilization under heavy load conditions. The performance results also indicate that delivery of multimedia traffic with a high quality-of-service can be achieved with our solution.     

Hybrid ALOHA: A Novel MAC Protocol

This paper considers cross-layer medium access control (MAC) protocol design in wireless networks. Taking a mutually interactive MAC-PHY perspective, we aim to design an MAC protocol that is in favor of the physical (PHY) layer information transmission, and the improved PHY, in turn, can improve the MAC performance. More specifically, we propose a novel MAC protocol, named hybrid ALOHA, which makes it possible for collision-free channel estimation and simultaneous multiuser transmission. The underlying argument is as follows: As long as good channel estimation can be achieved, advanced signal processing does allow effective signal separation given that the multiuser interference is limited to a certain degree. Comparing with traditional ALOHA, there are more than one pilot subslots in each hybrid ALOHA slot. Each user randomly selects a pilot subslot for training sequence transmission. Therefore, it is possible for different users to transmit their training sequences over nonoverlapping pilot subslots and achieving collision-free channel estimation. Relying mainly on the general multipacket reception (MPR) model, in this paper, quantitative analysis is conducted for the proposed hybrid ALOHA protocol in terms of throughput, stability, as well as delay behavior. It is observed that significant performance improvement can be achieved in comparison with the traditional ALOHA protocol based either on the collision model or the MPR model.     

A Sensor Network Cross-Layer Power Control Algorithm that Incorporates Multiple-Access Interference

This paper presents a wireless sensor network (WSN) transmit power control algorithm designed to minimize WSN node energy consumption. The algorithm determines transmit power levels using an optimization that accounts for energy consumed by the physical and link layers of the protocol stack. This cross-layer optimization incorporates a physical layer model that uses knowledge of the WSN medium access control (MAC) layer algorithm to accurately model multiple access interference (MAI). Analytical and simulation results show that accounting for MAI in this fashion results in a significant energy savings relative to comparable WSN power control algorithms.     

水声网络中Aloha协议与MACA协议的比较分析

浅海水声信道的快衰落、长延时使水声网络媒介访问控制（MAC）层协议的性能受到了较大的负面影响。为了能更好地将无线传感器网络的MAC协议适用于水声网络,本文着重对Aloha协议和冲突避免多址接入（MACA）协议进行改进分析,借助通信网络仿真工具OPNET,比较两者在吞吐量、时延、能量损耗和分组丢失率4方面的性能结果。仿真结果表明：与Aloha协议相比,MACA协议能更好地提高性能,有利于在水声网络中使用。     

Modified Distributed Laxity Based Priority Scheduling Scheme

This paper proposes a medium access control (MAC) protocol for mobile Adhoc networks (MANET). The MAC layer is responsible for selecting the next packet to be transmitted and the timing of its transmission. Various new factors are introduced to determine the priority of the flow. The back-off mechanism devised by us grants node access to the channel based on the rank of its highest priority packets. It is clear that the proposed algorithm works better than the existing distributed laxity based priority-scheduling scheme and the same is proven using the simulation results using Glomosim.     

GRAPO—optimized group randomly addressed polling for wireless data network

This paper presents a MAC (medium access control) layer protocol GRAPO (optimized group randomly addressed polling) for wireless (local area) data network. GRAPO statistically optimizes the original version of GRAP proposed earlier [6, 7, 9] to deliver smooth converging and better throughput/delay performance. It is a good candidate of MAC protocol for wireless LANs and other wireless network applications to serve time bounded services.     

Medium access control protocols for wireless mobile ad hoc networks: issues and approaches

In this article, a comprehensive survey of the medium access control (MAC) approaches for wireless mobile ad hoc networks is presented. The complexity in MAC design for wireless ad hoc networks arises due to node mobility, radio link vulnerability and the lack of central coordination. A series of studies on MAC design has been conducted in the literature to improve medium access performance in different aspects as identified by the different performance metrics. Tradeoffs among the different performance metrics (such as between throughput and fairness) dictate the design of a suitable MAC protocol. We compare the different proposed MAC approaches, identify their problems and discuss the possible remedies. The interactions among the MAC and the higher layer protocols such as routing and transport layer protocols are discussed and some interesting research issues are also identified. Copyright © 2003 John Wiley & Sons, Ltd.     

Location‐aided medium access control for low data rate UWB wireless sensor networks

This paper presents a distributed medium access control (MAC) protocol for low data rate ultra‐wideband (UWB) wireless sensor networks (WSNs), named LA‐MAC. Current MAC proposal is closely coupled to the IEEE 802.15.4a physical layer and it is based on its Impulse‐Radio (IR) paradigm. LA‐MAC protocol amplifies its admission control mechanism with location‐awareness, by exploiting the ranging capability of the UWB signals. The above property leads to accurate interference predictions and blocking assessments that each node in the network can perform locally, limiting at the same time the actions needed to be performed towards the admission phase. LA‐MAC is evaluated through extensive simulations, showing a significant improvement in many critical parameters, such as throughput, admission ratio, energy consumption, and delay, under different traffic load conditions. Copyright © 2010 John Wiley & Sons, Ltd.     

Cross-layer analysis of protocol delay in mobile devices receiving BCMCS

Broadcast and multicast services allow the high-speed delivery of multimedia content to multiple subscribers over CDMA2000 wireless networks. This relies on a high-rate broadcast packet data system with an air interface governed by two interacting protocols: the medium access control (MAC) protocol specifies the methods of multiplexing and of forward error correction used to reduce the radio link error-rate seen by the higher layers; and the security protocol specifies the procedures used to encrypt and decrypt content, following the Advanced Encryption Standard. We investigated the mutual effect of these protocols, in the context of an ARM9-based mobile platform, and their influence on delay. This allowed us to propose a novel analytic model that can predict the total delay by summing the separate but related delays incurred by implementations of the MAC and security protocols with particular parameters. This cross-layer model includes the characteristics of error control in the MAC layer and the varying condition of the fading channel in the physical layer. We can use this model to estimate the size of data buffers that mobiles require to provide a seamless multimedia service.     

IEEE 802.11 medium access control enhancements based on simultaneous multiple‐input multiple‐output bandwidth sharing

The demand for higher data rate has spurred the adoption of multiple‐input multiple‐output (MIMO) transmission techniques in IEEE 802.11 products. MIMO techniques provide an additional spatial dimension that can significantly increase the channel capacity. A number of multiuser MIMO system have been proposed, where the multiple antenna at the physical layer are employed for multiuser access, allowing multiple users to share the same bandwidth. As these MIMO physical layer technologies further evolve, the usable bandwidth per application increases; hence, the average service time per application decreases. However, in the IEEE 802.11 distributed coordination function‐based systems, a considerable amount of bandwidth is wasted during the medium access and coordination process. Therefore, as the usable bandwidth is enhanced using MIMO technology, the bandwidth wastage of medium access and coordination becomes a significant performance bottleneck. Hence, there is a fundamental need for bandwidth sharing schemes at the medium access control (MAC) layer where multiple connections can concurrently use the increased bandwidth provided by the physical layer MIMO technologies. In this paper, we propose the MIMO‐aware rate splitting (MRS) MAC protocol and examine its behavior under different scenarios. MRS is a distributed MAC protocol where nodes locally cooperate with one another to share bandwidth via splitting the spatial channels of MIMO systems. Simulation results of MRS protocol are obtained and compared with those of IEEE 802.11n protocol. We show that our proposed MRS scheme can significantly outperform the IEEE 802.11n in medium access delay and throughput. Copyright © 2012 John Wiley & Sons, Ltd.     

FPS‐MAC: Fuzzy priority scheduling‐based MAC protocol for intelligent monitoring systems

Recent advances in microelectronics have encouraged the implementation of a wireless sensor network (WSN) in intelligent monitoring systems (IMSs). The IMS for time‐critical applications requires timely and reliable data delivery without sacrificing the energy efficiency of the network. This paper proposes FPS‐MAC, a fuzzy priority scheduling‐based medium access control protocol, designed for event critical traffic in hierarchical WSN. The FPS‐MAC allows time‐critical event traffic to opportunistically steal the data slots allocated for periodic data traffic in event‐based situations. Additionally, a fuzzy logic‐based slot scheduling mechanism is introduced to provide guaranteed and timely medium access to emergency traffic load and ensures the quality‐of‐service (QoS) requirements of IMSs. Both analytical and simulation results for data throughput, energy consumption, and transmission delay of FPS‐MAC, TLHA, E‐BMA, and BMA‐RR have been analyzed to demonstrate the superiority of the proposed FPS‐MAC protocol.