Paper Info
Title
Is ALOHA causing power law delays?
Abstract
Renewed interest in ALOHA-based Medium Access Control (MAC) protocols stems from their proposed applications to wireless ad hoc and sensor networks that require distributed and low complexity channel access algorithms. In this paper, unlike in the traditional work that focused on mean value (throughput) and stability analysis, we study the distributional properties of packet transmission delays over an ALOHA channel. We discover a new phenomenon showing that a basic finite population ALOHA model with variable size (exponential) packets is characterized by power law transmission delays, possibly even resulting in zero throughput. This power law effect might be diminished, or perhaps eliminated, by reducing the variability of packets. However, we show that even a slotted (synchronized) ALOHA with packets of constant size can exhibit power law delays when the number of active users is random. From an engineering perspective, our results imply that the variability of packet sizes and number of active users need to be taken into consideration when designing robust MAC protocols, especially for ad-hoc/sensor networks where other factors, such as link failures and mobility, might further compound the problem.
Year
DOI
Venue
2007
10.1007/978-3-540-72990-7_98
International Teletraffic Congress
Keywords
Field
DocType
power law effect,active user,power law transmission delay,power law delay,basic finite population aloha,low complexity channel access,constant size,aloha channel,sensor network,packet size,power law,heavy tailed distribution,power laws,stability analysis
Population,Aloha,Computer science,Network packet,Computer network,Communication channel,Real-time computing,Access control,Throughput,Wireless ad hoc network,Wireless sensor network
Conference
Volume
ISSN
Citations 
4516
0302-9743
17
PageRank 
References 
Authors
1.64
9
2
Name
Order
Citations
PageRank
Predrag R. Jelenkovic121929.99
Jian Tan2171.64