scholarly journals Improvement of Network Utility and Energy Efficiency in DSME based Internet of Things Networks

This paper provides a comparison between IEEE 802.11 and IEEE 802.15.4e standards in the context of Internet of Things (IoT). These emerging standards are the amendments of IEEE 802.11 and IEEE 802.15.4 to support IoT based applications. The 802.11 has a channel access scheme, Distributed coordination function (DCF). On the other hand, IEEE 802.15.4e introduces five MAC behavior mode. Among these five modes, DSME is well suited for IoT. A comparison between these two standards is discussed in this paper by using an analytical model and are validated through ns-3 simulations. Results show that the DSME show significant improvement in the performance of DSME when compared to the legacy IEEE 802.11 DCF.

2008 ◽  
Vol 2008 ◽  
pp. 1-17 ◽  
Author(s):  
Yutae Lee ◽  
Min Young Chung ◽  
Tae-Jin Lee

Carrier sense multiple access with collision avoidance (CSMA/CA) methods are considered to be attractive MAC protocols for wireless LANs. IEEE 802.11 distributed coordination function (DCF) is a random channel access scheme based on CSMA/CA method and the binary slotted exponential backoff procedure to reduce the packet collision. In this paper, we propose a new analytical model for a nonsaturated IEEE 802.11 DCF network and evaluate its performance. We verify our model using simulations and show that our results agree with the simulations.


Author(s):  
Nurul I. Sarkar

One of the limitations of the IEEE 802.11 distributed coordination function (DCF) protocol is its low bandwidth utilization under medium-to-high traffic loads resulting in low throughput and high packet delay. To overcome performance problems, traditional IEEE 802.11 DCF (“DCF”) protocol is modified to the buffer unit multiple access (BUMA) protocol. The BUMA protocol achieves a better system performance by introducing a temporary buffer unit at the medium access control (MAC) layer to accumulate multiple packets and combine them into a single packet (with a header and a trailer) before transmission. This paper provides an in-depth performance evaluation (by simulation) of BUMA for multiuser ad hoc and infrastructure networks. Results obtained show that the BUMA is more efficient than that of DCF. The BUMA protocol is simple and its algorithm (software) can be upgraded to 802.11 networks requiring no hardware changes. The BUMA protocol is described and simulation results are presented to verify the performance.


2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Radha Ranganathan ◽  
Kathiravan Kannan

IEEE 802.11 is the de facto standard for medium access over wireless ad hoc network. The collision avoidance mechanism (i.e., random binary exponential backoff—BEB) of IEEE 802.11 DCF (distributed coordination function) is inefficient and unfair especially under heavy load. In the literature, many algorithms have been proposed to tune the contention window (CW) size. However, these algorithms make every node select its backoff interval between [0, CW] in a random and uniform manner. This randomness is incorporated to avoid collisions among the nodes. But this random backoff interval can change the optimal order and frequency of channel access among competing nodes which results in unfairness and increased delay. In this paper, we propose an algorithm that schedules the medium access in a fair and effective manner. This algorithm enhances IEEE 802.11 DCF with additional level of contention resolution that prioritizes the contending nodes according to its queue length and waiting time. Each node computes its unique backoff interval using fuzzy logic based on the input parameters collected from contending nodes through overhearing. We evaluate our algorithm against IEEE 802.11, GDCF (gentle distributed coordination function) protocols using ns-2.35 simulator and show that our algorithm achieves good performance.


2013 ◽  
Vol 380-384 ◽  
pp. 1202-1209
Author(s):  
Xuan Chen ◽  
Yu Bin Xu ◽  
Lin Ma

A queuing model is proposed to analyze the performance of IEEE 802.11 Distributed Coordination Function (DCF). By regarding the network performance in the unsaturated case as the expected mean of the network performance in the different saturated cases, the proposed model extends the application scenarios from the saturated case to the nonsaturated case. The queuing model can be used to analyze the network performance and QoS parameters of the stations for different traffic conditions. In addition, this model also applies to the cases in shadow channels. Compared to the existing work based on the classic Markov model, the proposed model is more general and can be used in more complex and practical scenarios.


Author(s):  
K. Chetan ◽  
P. Venkataram ◽  
R. Sircar

Providing support for QoS at the MAC layer in the IEEE 802.11 is one of the very active research areas. There are various methods that are being worked out to achieve QoS at MAC level. In this article we describe a proposed enhancement to the DCF (distributed coordination function) access method to provide QoS guarantee for wireless multimedia applications.


Sign in / Sign up

Export Citation Format

Share Document