This paper presents Span, a power saving technique for multi-hop ad hoc wireless networks that reduces energy consumption without significantly diminishing the capacity or connectivity of the network. Span builds on the observation that when a region of a shared-channel wireless network bag a sufficient density of nodes, only a small number of them need be on at any time to forward traffic for active connections.Span is a distributed, randomized algorithm where nodes make local decisions on whether to sleep, or to join a forwarding backbone as a coordinator. Each node bases its decision on an estimate of how many of its neighbors will benefit from it being awake, and the amount of energy available to it. We give a randomized algorithm where coordinators rotate with time, demonstrating how localized node decisions lead to a connected, capacity-preserving global topology.Improvement in system lifetime due to Span increases as the ratio of idle-to-sleep energy consumption increases, and increases as the density of the network increases. For example, our simulations show that with a practical energy model, system lifetime of an 802.11 network in power saving mode with Span is a factor of two better than without. Span integrates nicely with 802.11—when run in conjunction with the 802.11 power saving mode, Span improves communication latency, capacity, and system lifetime.

https://www.cs.ucla.edu/classes/fall03/cs218/paper/p85-chen.pdf

Span: An energy-efficient coordination algorithm for topology maintenance in Ad Hoc wireless networks

Energy-aware design and evaluation of network protocols requires knowledge of the energy consumption behavior of actual wireless interfaces. But little practical information is available about the energy consumption behavior of well-known wireless network interfaces and device specifications do not provide information in a form that is helpful to protocol developers. This paper describes a series of experiments which obtained detailed measurements of the energy consumption of an IEEE 802.11 wireless network interface operating in an ad hoc networking environment. The data is presented as a collection of linear equations for calculating the energy consumed in sending, receiving and discarding broadcast and point-to-point data packets of various sizes. Some implications for protocol design and evaluation in ad hoc networks are discussed.

/pdf/investigating-the-energy-consumption-of-a-wireless-network-1ofvecb03i.pdf

Investigating the energy consumption of a wireless network interface in an ad hoc networking environment

In this paper we present X-MAC, a low power MAC protocol for wireless sensor networks (WSNs). Standard MAC protocols developed for duty-cycled WSNs such as BMAC, which is the default MAC protocol for TinyOS, employ an extended preamble and preamble sampling. While this “low power listening” approach is simple, asynchronous, and energy-efficient, the long preamble introduces excess latency at each hop, is suboptimal in terms of energy consumption, and suffers from excess energy consumption at nontarget receivers. X-MAC proposes solutions to each of these problems by employing a shortened preamble approach that retains the advantages of low power listening, namely low power communication, simplicity and a decoupling of transmitter and receiver sleep schedules. We demonstrate through implementation and evaluation in a wireless sensor testbed that X-MAC’s shortened preamble approach significantly reduces energy usage at both the transmitter and receiver, reduces per-hop latency, and offers additional advantages such as flexible adaptation to both bursty and periodic sensor data sources.

X-MAC: A Short Preamble MAC Protocol for Duty-Cycled Wireless Sensor Networks ; CU-CS-1008-06

In this paper we present X-MAC, a low power MAC protocol for wireless sensor networks (WSNs). Standard MAC protocols developed for duty-cycled WSNs such as BMAC, which is the default MAC protocol for TinyOS, employ an extended preamble and preamble sampling. While this "low power listening" approach is simple, asynchronous, and energy-efficient, the long preamble introduces excess latency at each hop, is suboptimal in terms of energy consumption, and suffers from excess energy consumption at nontarget receivers. X-MAC proposes solutions to each of these problems by employing a shortened preamble approach that retains the advantages of low power listening, namely low power communication, simplicity and a decoupling of transmitter and receiver sleep schedules. We demonstrate through implementation and evaluation in a wireless sensor testbed that X-MAC's shortened preamble approach significantly reduces energy usage at both the transmitter and receiver, reduces per-hop latency, and offers additional advantages such as flexible adaptation to both bursty and periodic sensor data sources.

/pdf/x-mac-a-short-preamble-mac-protocol-for-duty-cycled-wireless-3g39p5984w.pdf

X-MAC: a short preamble MAC protocol for duty-cycled wireless sensor networks

This document provides updates to IEEE Std 802.16's MIB for the MAC, PHY and asso- ciated management procedures in order to accommodate recent extensions to the standard.

IEEE Standard for Local and Metropolitan Area Networks Part 16: Air Interface for Fixed Broadband Wireless Access Systems Draft Amendment: Management Information Base Extensions

A mobile ad hoc network (or manet) is a group of mobile, wireless nodes which cooperatively form a network independent of any fixed infrastructure or centralized administration. In particular, a manet has no base stations: a node communicates directly with nodes within wireless range and indirectly with all other nodes using a dynamically-computed, multi-hop route via the other nodes of the manet. Simulation and experimental results are combined to show that energy and bandwidth are substantively different metrics and that resource utilization in manet routing protocols is not fully addressed by bandwidth-centric analysis. This report presents a model for evaluating the energy consumption behavior of a mobile ad hoc network. The model was used to examine the energy consumption of two well-known manet routing protocols. Energy-aware performance analysis is shown to provide new insights into costly protocol behaviors and suggests opportunities for improvement at the protocol and link layers.

/pdf/an-energy-consumption-model-for-performance-analysis-of-2oou5h36kn.pdf

An energy consumption model for performance analysis of routing protocols for mobile ad hoc networks

An ad hoc network must operate independent of a preestablished or centralized network management infrastructure, while still providing administrative services needed to support applications. Address allocation, name resolution, service location, authentication, and access control policies represent just some of the functionality that must be supported-without preconfiguration or centralized services. In order to solve these problems, it is necessary to leverage some aspect of the environment in which the network operates. We introduce the notion of a spontaneous network, created when a group of people come together for some collaborative activity. In this case, we can use the human interactions associated with the activity in order to establish a basic service and security infrastructure. We structure our discussion around a practical real-world scenario illustrating the use of such a network, identifying the key challenges involved and some of the techniques that can be used to address them.

Spontaneous networking: an application oriented approach to ad hoc networking

A Mobile Ad hoc NETwork (manet) is a mobile, multi-hop wireless
network which is capable of autonomous operation. It is characterized
by energy-constrained nodes, bandwidth-constrained, variable-capacity
wireless links and dynamic topology, leading to frequent and
unpredictable connectivity changes.

In the absence of a fixed infrastructure, manet nodes cooperate to
provide routing services, relying on each other to forward packets to
their destination. Routing protocols designed for the fixed network
are not effective in the dynamic and resource-constrained manet
environment; many alternative routing protocols have been suggested.

This report provides an overview of a number of manet routing
protocols. More importantly, it defines a taxonomy that is suitable
for examining a wide variety of protocols in a structured way and
exploring tradeoffs associated with various design choices. The
emphasis is on practical design and implementation issues rather than
complexity analysis.

A Taxonomy for Routing Protocols in Mobile Ad Hoc Networks

The rapid growth of new radio technologies for Smart City/Building/Home applications means that models of cross-technology interference are needed to inform the development of higher layer protocols and applications. We systematically investigate interference interactions between LoRa and IEEE 802.15.4g networks. Our results show that LoRa can obtain high packet reception rates, even in presence of strong IEEE 802.15.4g interference. IEEE 802.15.4g is also shown to have some resilience to LoRa interference. Both effects are highly dependent on the LoRa radio's spreading factor and bandwidth configuration, as well as on the channelization. The results are shown to arise from the interaction between the two radios' modulation schemes. The data have implications for the design and analysis of protocols for both radio technologies.

Laura Marie Feeney

Papers

Investigating the energy consumption of a wireless network interface in an ad hoc networking environment

An energy consumption model for performance analysis of routing protocols for mobile ad hoc networks

Spontaneous networking: an application oriented approach to ad hoc networking

A Taxonomy for Routing Protocols in Mobile Ad Hoc Networks

Investigating interference between LoRa and IEEE 802.15.4g networks