Showing papers on "Wireless ad hoc network published in 1998"
25 Oct 1998
TL;DR: The results of a derailed packet-levelsimulationcomparing fourmulti-hopwirelessad hoc networkroutingprotocols, which cover a range of designchoices: DSDV,TORA, DSR and AODV are presented.
Abstract: An ad hoc networkis a collwtion of wirelessmobilenodes dynamically forminga temporarynetworkwithouttheuseof anyexistingnetworkirrfrastructureor centralizedadministration.Dueto the limitedtransmissionrange of ~vlrelessnenvorkinterfaces,multiplenetwork“hops”maybe neededfor onenodeto exchangedata ivithanotheracrox thenetwork.Inrecentyears, a ttiery of nelvroutingprotocols~geted specificallyat this environment havebeen developed.but little pcrfomrartwinformationon mch protocol and no ralistic performancecomparisonbehvwrrthem ISavailable. ~Is paper presentsthe results of a derailedpacket-levelsimulationcomparing fourmulti-hopwirelessad hoc networkroutingprotocolsthatcovera range of designchoices: DSDV,TORA, DSR and AODV. \Vehave extended the /~r-2networksimulatorto accuratelymodelthe MACandphysical-layer behaviorof the IEEE 802.1I wirelessLANstandard,includinga realistic wtrelesstransmissionchannelmodel, and present the resultsof simulations of net(vorksof 50 mobilenodes.
5,147 citations
25 Oct 1998
TL;DR: An approach to utilize location information (for instance, obtained using the global positioning system) to improve performance of routing protocols for ad hoc networks is suggested.
Abstract: A mobile ad hoc network consists of wireless hosts that may move often. Movement of hosts results in a change in routes, requiring some mechanism for determining new routes. Several routing protocols have already been proposed for ad hoc networks. This report suggests an approach to utilize location information (for instance, obtained using the global positioning system) to improve performance of routing protocols for ad hoc networks.
2,854 citations
25 Oct 1998
TL;DR: In this article, the authors present a case for using new power-aware metn.cs for determining routes in wireless ad hoc networks and show that using these new metrics ensures that the mean time to node failure is increased si~cantly.
Abstract: b this paper we present a case for using new power-aware metn.cs for determining routes in wireless ad hoc networks. We present five ~erent metriw based on battery power consumption at nodw. We show that using th=e metrics in a shortest-cost routing algorithm reduces the cost/packet of routing packets by 5-30% over shortwt-hop routing (this cost reduction is on top of a 40-70% reduction in energy consumption obtained by using PAMAS, our MAC layer prtocol). Furthermore, using these new metrics ensures that the mean time to node failure is increased si~cantly. An interesting property of using shortest-cost routing is that packet delays do not increase. Fintiy, we note that our new metrim can be used in most tradition routing protocols for ad hoc networks.
1,885 citations
01 Jul 1998
TL;DR: A new multiaccess protocol based on the original MACA protocol with the adition of a separate signalling channel that conserves battery power at nodes by intelligently powering off nodes that are not actively transmitting or receiving packets.
Abstract: In this paper we develop a new multiaccess protocol for ad hoc radio networks. The protocol is based on the original MACA protocol with the adition of a separate signalling channel. The unique feature of our protocol is that it conserves battery power at nodes by intelligently powering off nodes that are not actively transmitting or receiving packets. The manner in which nodes power themselves off does not influence the delay or throughput characteristics of our protocol. We illustrate the power conserving behavior of PAMAS via extensive simulations performed over ad hoc networks containing 10-20 nodes. Our results indicate that power savings of between 10% and 70% are attainable in most systems. Finally, we discuss how the idea of power awareness can be built into other multiaccess protocols as well.
1,257 citations
01 Jan 1998
TL;DR: A short-range radio link that is small enough to fit inside any electronic device or machine, that provides local connectivity, and that creates a (worldwide) micro-scale web.
Abstract: that is small enough to fit inside any electronic device or machine, that provides local connectivity, and that creates a (worldwide) micro-scale web. What applications might you use it in? In 1994, Ericsson Mobile Communications AB in Lund, Sweden, initiated a study to investigate the feasibility of a low-power, low-cost radio interface between mobile phones and their accessories. The intention was to eliminate cables between phones and PC cards, wireless headsets, and so forth. The study was part of a larger project that investigated multi-communicators connected to the cellular network via cellular telephones. The last link in the connection between a communicator and the cellular network was a short-range radio link to the phone—thus, the link was called the multicommunicator link or MC link. As the MC link project progressed, it became clear that there was no limit to the kinds of application that could use a short-range radio link. Cheap, short-range radios would make wireless communication between portable devices economically feasible. Current portable devices use infrared links (IrDA) to communicate with each other. Although infrared transceivers are inexpensive, they • have limited range (typically one to two meters); • are sensitive to direction and require direct line-of-sight; • can in principle only be used between two devices. By contrast, radios have much greater range, can propagate around objects and through various materials, and connect to many devices simultaneously. What is more, radio interfaces do not require user interaction. In the beginning of 1997, when designers had already begun work on an MC link
591 citations
01 Oct 1998
TL;DR: This paper studies the performance of route query control mechanisms for the recently proposed Zone Routing Protocol (ZRP) for ad-hoc networks and demonstrates how certain combinations of these techniques can be applied to single channel or multiple channel ad-Hoc networks to improve both the delay and control traffic performance of the ZRP.
Abstract: In this paper, we study the performance of route query control mechanisms for the recently proposed Zone Routing Protocol (ZRP) for ad-hoc networks. The ZRP proactively maintains routing information for a local neighborhood (routing zone), while reactively acquiring routes to destinations beyond the routing zone. This hybrid routing approach has the potential to be more efficient in the generation of control traffic than traditional routing schemes. However, without proper query control techniques, the ZRP can actually produce more traffic than standard flooding protocols.Our proposed query control schemes exploit the structure of the routing zone to provide enhanced detection (Query Detection (QD1/QD2)), termination (Loop-back Termination (LT), Early Termination (ET)) and prevention (Selective Bordercasting (SBC)) of overlapping queries. We demonstrate how certain combinations of these techniques can be applied to single channel or multiple channel ad-hoc networks to improve both the delay and control traffic performance of the ZRP. Our query control mechanisms allow the ZRP to provide routes to all accessible network nodes with only a fraction of the control traffic generated by purely proactive distance vector and purely reactive flooding schemes, and with a response time as low as 10% of a flooding route query delay.
514 citations
16 Dec 1998
TL;DR: The main result is this: if n nodes are located randomly, uniformly i.i.d., in a disc of unit area in /spl Rfr//sup 2/ and each node transmits at a power level so as to cover an area of /spl pi/r/Sup 2/=(log n + c(n))/n, then the resulting network is asymptotically connected with probability one as the number of nodes in the network goes to infinity.
Abstract: In wireless data networks the range of each transmitter, and thus its power level, needs to be high enough to reach the intended receivers, while being low enough to avoid generating interference for other receivers on the same channel. If the nodes in the network are assumed to cooperate, perhaps in a distributed and decentralized fashion, in routing each others' packets, as is the case in ad hoc wireless networks, then each node should transmit with just enough power to guarantee connectivity of the overall network. Towards this end, we determine the critical power at which a node in the network needs to transmit in order to ensure that the network is connected with probability one as the number of nodes in the network goes to infinity. Our main result is this: if n nodes are located randomly, uniformly i.i.d., in a disc of unit area in /spl Rfr//sup 2/ and each node transmits at a power level so as to cover an area of /spl pi/r/sup 2/=(log n + c(n))/n, then the resulting network is asymptotically connected with probability one if and only if c(n)/spl rarr/+/spl infin/.
352 citations
12 Oct 1998
TL;DR: It is observed that the new generation of on-demand routing protocols use a much lower routing load, however the traditional link state and distance vector protocols provide, in general, better packet delivery and delay performance.
Abstract: We evaluate several routing protocols for mobile, wireless, ad hoc networks via packet level simulations. The protocol suite includes routing protocols specifically designed for ad hoc routing, as well as more traditional protocols, such as link state and distance vector used for dynamic networks. Performance is evaluated with respect to fraction of packets delivered, end-to-end delay and routing load for a given traffic and mobility model. It is observed that the new generation of on-demand routing protocols use a much lower routing load. However the traditional link state and distance vector protocols provide, in general, better packet delivery and delay performance.
332 citations
TL;DR: This article is part of a continuing series to discuss ongoing activities within the mobile ad hoc networking (MANET) working group (WG) of the IETF.
Abstract: This article is part of a continuing series to discuss ongoing activities within the mobile ad hoc networking (MANET) working group (WG) of the IETF. This article provides a brief overview of recent events.
248 citations
26 May 1998
TL;DR: It is observed that in the event of route failures, as the route re-establishment time increases, the use of feedback provides significant gains in throughput as well as savings in unnecessary packet transmissions.
Abstract: Ad-hoc networks are completely wireless networks of mobile hosts, in which the topology rapidly changes due to the movement of mobile hosts. This frequent topology may lead to sudden packet losses and delays. Transport protocols like TCP have been built mainly for reliable, fixed networks. Hence, when used in ad-hoc networks, TCP misinterprets this loss as congestion and invokes congestion control. This leads to unnecessary retransmissions and loss of throughput. To overcome this problem, a feedback scheme is proposed, so that the source can distinguish between route failure and network congestion. When a route is disrupted, the source is sent a route failure notification (RFN) packet, allowing it to freeze its timers and stop sending packets. When the route is re-established, the source is informed through a route re-establishment notification (RRN) packet, upon which it resumes by unfreezing timers and continuing packet transmissions. The simulated performance of TCP on ad-hoc networks with and without feedback is compared and reported. It is observed that in the event of route failures, as the route re-establishment time increases, the use of feedback provides significant gains in throughput as well as savings in unnecessary packet transmissions. Several further enhancements and directions for future work are also sketched.
223 citations
11 Oct 1998
TL;DR: The simulation results show that the bandwidth routing algorithm is very useful in extending the ATM virtual circuit service to the wireless network and enables an efficient call admission control.
Abstract: The emergence of nomadic applications have generated a lot of interest in wireless network infrastructures which support multimedia services. We propose a bandwidth routing algorithm for multimedia support in a multihop wireless network. This network can be interconnected to wired networks (e.g. ATM or the Internet) or stand alone. Our bandwidth routing includes bandwidth calculation and reservation schemes. Under such a routing algorithm, we can derive a route to satisfy the bandwidth requirement for the QoS constraint. At a source node, the bandwidth information can be used to decide to accept a new call or not immediately. This is specially important to carry out a fast handoff when interconnecting to an ATM backbone infrastructure. It enables an efficient call admission control. The simulation results show that the bandwidth routing algorithm is very useful in extending the ATM virtual circuit service to the wireless network. Different types of QoS traffic can be integrated in such a dynamic radio network with high performance.
01 Jan 1998
TL;DR: An ad-hoc network is a temporary network without any form of centralized administration where each node acts as a node in the network, and multiple hops might be necessary to reach other nodes in thenetwork.
Abstract: An ad-hoc network is a temporary network without any form of centralized administration Multiple hops might be necessary to reach other nodes in the network For this reason, each node acts bo
Patent•
30 Sep 1998
TL;DR: In this article, a beacon generator is installed in the vicinity of an access point of the WLAN infrastructure, and generates a wireless beacon in a portion of the ISM band that does not overlap that portion used by WLAN.
Abstract: A repetitively pulsed beacon based mechanism prevents interference between wireless communication devices of users of a band wireless local area network WLAN, and wireless communication devices of ad hoc networks using the same ISM band. A beacon generator is installed in the vicinity of an access point of the WLAN infrastructure, and generates a wireless beacon in a portion of the ISM band that does not overlap that portion used by the WLAN. A beacon responsive radio control mechanism, installed in each ad hoc radio, monitors the beacon channel for the presence of the wireless beacon. In response to detecting the beacon, the radio control mechanism adjusts the operation of its ad hoc radio, to avoid simultaneous use of the same portion of the ISM band as the WLAN. In one example, the ad hoc radio is adjusted so that it transmits within a selected portion of the ISM band other than that used by the WLAN.
07 Sep 1998
TL;DR: A wireless medium access protocol that provides significantly better channel utilization, delay, and delay variance characteristics compared to the IEEE 802.11 standard is presented.
Abstract: This paper evaluates the performance of a class of multiple-access algorithms for wireless medium access in shared-channel multi-cell and ad hoc network environments. Based on the collision avoidance and fairness properties of the evaluated algorithms, this paper presents a wireless medium access protocol that provides significantly better channel utilization, delay, and delay variance characteristics compared to the IEEE 802.11 standard.
08 Sep 1998
TL;DR: A new multi-access protocol for multi-hop radio networks that is energy conserving and based on the manner in which nodes power themselves off, which indicates that power savings of up to 70% are attainable in most systems.
Abstract: In this paper we develop a new multi-access protocol for multi-hop radio networks. The unique feature of our protocol is that it is energy conserving. Radios that are not actively transmitting or receiving a packet power themselves off. The manner in which nodes power themselves off does not influence the delay or throughput characteristics of our protocol. Simulation results indicate that power savings of between 10% and 70% are attainable in most systems.
TL;DR: This work introduces a self organizing network structure called a spine and proposes a spine-based routing infrastructure for routing in ad hoc networks and proposes two spine routing algorithms: Optimal Spine Routing (OSR), which uses full and up-to-date knowledge of the network topology, and (b) Partial-knowledge SpineRouting (PSR, which uses partialknowledge of thenetwork topology.
Abstract: An ad hoc network is a multihop wireless network in which mobile hosts communicate without the support of a wired backbone for routing messages. We introduce a self organizing network structure called a spine and propose a spine-based routing infrastructure for routing in ad hoc networks. We propose two spine routing algorithms: (a) Optimal Spine Routing (OSR), which uses full and up-to-date knowledge of the network topology, and (b) Partial-knowledge Spine Routing (PSR), which uses partial knowledge of the network topology. We analyze the two algorithms and identify the optimality-overhead trade-offs involved in these algorithms.
Patent•
NEC1
TL;DR: In this paper, a link table has a plurality of entries comprising a host name, a link identifier indicating one of the wireless links, a network layer address and a data link layer address.
Abstract: In an ad hoc network of mobile hosts interconnectable by a number of wireless links, each mobile host includes a link table having a multiple entries each comprising a host name, a link identifier indicating one of the wireless links, a network layer address and a data link layer address. Each of the mobile hosts comprises a link table having a plurality of entries each comprising a host name, a link identifier indicating one of the wireless links, a network layer address and a data link layer address. Each mobile host is responsive to an entered destination host name for making a search through the link table, transmitting a frame containing the network layer and data link layer addresses of an entry of the link table on one of the wireless links which is indicated by the link identifier of this entry if this entry contains the destination host name. If the link table does not contain the destination host name, the mobile host scans the wireless links, broadcasts a link table request message on one of the scanned wireless links, receives a remote link table containing the destination host name, and transmits a frame containing network layer and data link layer addresses of the received link table on the wireless link on which the remote link table was received.
08 Nov 1998
TL;DR: This paper extends the shared tree concept to wireless, mobile, multihop networks for applications ranging from ad hoc networking to disaster recovery and battlefield, and proposes an adaptive scheme which combines shared tree and source tree benefits.
Abstract: Shared tree multicast is a well established concept used in several multicast protocols for wireline networks (e.g. core base tree, PIM sparse mode etc). In this paper, we extend the shared tree concept to wireless, mobile, multihop networks for applications ranging from ad hoc networking to disaster recovery and battlefield. The main challenge in wireless, mobile networks is the rapidly changing environment. We address this issue in our design by: (a) using "soft state"; (b) assigning different roles to nodes depending on their mobility (two level mobility model); (c) proposing an adaptive scheme which combines shared tree and source tree benefits. A detailed wireless simulation model is used to evaluate the proposed schemes and compare them with source based tree (as opposed to shared tree) multicast. The results show that shared tree protocols have low overhead and are very robust to mobility.
01 Jan 1998
TL;DR: A new single channel, time division multiple access (TDMA) based broadcast, scheduling protocol, termed the five-phase reservation protocol (FPRP), is presented for mobile ad hoc networks, and the node coloring process is seen to be as effective as an existing centralized approach.
Abstract: A new single channel, time division multiple access (TDMA) based broadcast, scheduling protocol, termed the five-phase reservation protocol (FPRP), is presented for mobile ad hoc networks. The protocol jointly and simultaneously performs the tasks of channel access and node broadcast scheduling. The protocol allows nodes to make reservations within TDMA broadcast schedules. It employs a contention-based mechanism with which nodes compete with each other to acquire TDMA slots. The FPRP is free of the "hidden terminal" problem, and is designed such that reservations can be made quickly and efficiently with negligible probability of conflict. It is fully-distributed and parallel (a reservation is made through a localized conversation between nodes in a 2-hop neighborhood), and is thus arbitrarily scalable. A "multihop ALOHA" policy is developed to support the FPRP. This policy uses a multihop, pseudo-Bayesian algorithm to calculate contention probabilities and enable faster convergence of the reservation procedure. The performance of the protocol is studied via simulation, and the node coloring process is seen to be as effective as an existing centralized approach. Some future work and applications are also discussed.
30 Jun 1998
TL;DR: This work proposes a self-organizing, dynamic infrastructure called a spine for efficient routing in ad hoc networks that encompasses a range of knowledge at each spine node, and identifies the trade-offs involved for routing at different points in this range.
Abstract: This work proposes a self-organizing, dynamic infrastructure called a spine for efficient routing in ad hoc networks. We present a scalable framework for routing that encompasses a range of knowledge at each spine node, and identify the trade-offs involved for routing at different points in this range. Our routing algorithm requires only partial topology information at each spine node, consisting of the spine structure, dependants of each spine node, propagation of long-lived links, and snooped routing information from ongoing flows. Through worst-case theoretical bounds and simulation of typical scenarios, we show that the spine-based routing with only partial topology information provides good routes at low overhead.
05 Oct 1998
TL;DR: This draft presents CEDAR, a Core-Extraction Distributed Ad hoc Routing algorithm for QoS routing in ad hoc network environments, and a QoS route computation algorithm that is executed at the core nodes using only locally available state.
Abstract: This draft presents CEDAR, a Core-Extraction Distributed Ad hoc Routing algorithm for QoS routing in ad hoc network environments. CEDAR has three key components: (a) the establishment and maintenance of a self-organizing routing infrastructure, called the "core", for performing route computations, (b) the propagation of the link-state of stable high-bandwidth links in the core through "increase/decrease" waves, and (c) a QoS route computation algorithm that is executed at the core nodes using only locally available state. Sivakumar, Sinha, Bharghavan [Page 1] INTERNET-DRAFT CEDAR Specification October 1998
07 Jun 1998
TL;DR: It is demonstrated that ZRP significantly reduces the delay and the amount of routing overhead by providing each node with continuous updates of its local neighborhood (routing zone) topology only.
Abstract: In this paper, we investigate the performance of a novel routing protocol, the zone routing protocol (ZRP), that was introduced in Haas (1997). The protocol is targeted at a special class of ad-hoc networks, which we refer to as the reconfigurable wireless networks (RWNs). RWNs are distinguished from other ad-hoc networks by their increased node mobility, larger number of nodes, and wider network span. We demonstrate that ZRP significantly reduces the delay and the amount of routing overhead by providing each node with continuous updates of its local neighborhood (routing zone) topology only. The structure of the routing zone is exploited to efficiently acquire routes on demand for destinations that lie beyond a node's routing zone. By adjusting a single parameter-the size of the routing zone-the ZRP can adapt to a variety of network operational conditions.
18 May 1998
TL;DR: This work presents a generalized approach called "k-hop cluster-based dynamic source routing", which is simple and can take actions on the host movements quickly and consider the overall channel utilization as well as host mobility.
Abstract: The existing wireless networks, such as cellular networks, personal communication services and mobile Internet protocol use the fixed network as their backbones. However in the situations like disaster rescues, wireless conferences in the hall, or battlefields, there exists no fixed communication infrastructure. Therefore, routing to send data packets to their destinations becomes very difficult. Distance vector and link state protocols used in the existing fixed networks are not suitable for supporting host movements. Variations of distance vector protocol, dynamic source muting schemes, and cluster-based schemes have been suggested to solve the muting problem in this entirely wireless network. However, since the link channel resource is very scarce, the muting scheme must consider the overall channel utilization as well as host mobility. We present a generalized approach called "k-hop cluster-based dynamic source routing". This approach is simple and can take actions on the host movements quickly.
07 Jun 1998
TL;DR: The Group Allocation Multihop Multiple Access (GAMMA) protocol is presented; this protocol schedules data traffic over a multihop, multi-channel, wireless network.
Abstract: The Group Allocation Multihop Multiple Access (GAMMA) protocol is presented; this protocol schedules data traffic over a multihop, multi-channel, wireless network. GAMMA provides excellent performance and remains stable under all network load levels by dividing the channel into cycles; each cycle is composed of a combination of contention and data slots. Every station in the network has a unique channel for receiving data. Each station maintains a set of stations called the "transmission group", only members of this group are allowed to transmit data collision-free to the station maintaining the group.
TL;DR: An overview of infrared technology is given and the IEEE 802.11 specification in detail is described in detail, presenting a historical perspective of its development.
Abstract: The new IEEE 802.11 standard for wireless local area networks defines a specification for an infrared physical layer. This article gives an overview of infrared technology and describes the IEEE 802.11 specification in detail, presenting a historical perspective of its development. The infrared physical layer was designed for diffuse systems supporting two data rates (1 and 2 Mb/s) and includes provisions for a smooth migration to higher data rates. The specification is suitable for low-cost transceivers but allows interoperability with higher-performance systems. The main application envisaged for IEEE 802.11 infrared wireless local area networks is ad hoc networks.
01 Jan 1998
TL;DR: Simulations have shown that the performance of the E-TDMA protocol is close to that of centralized algorithms, while being insensitive to network size in terms of scheduling quality and scheduling overhead.
Abstract: A new single channel, time division multiple access (TDMA) scheduling protocol, termed “EvolutionaryTDMA”, is presented for mobile ad hoc networks. The protocol allows nodes in an ad hoc network to reserve conflict-free TDMA slots for transmission to their neighbors. Two topology-dependent schedules are generated and maintained by the protocol: a broadcast schedule suitable for network control traffic and a mixed schedule which combines unicast, multicast and broadcast transmissions for user data traffic. The schedules are frequently updated in an evolutionary manner to maintain conflict-free transmissions. The protocol executes across the entire network simultaneously in a fully-distributed and parallel fashion. Traffic prioritization and Quality of Service (QoS) can be supported. Simulations have shown that the performance of the E-TDMA protocol is close to that of centralized algorithms, while being insensitive to network size in terms of scheduling quality and scheduling overhead. It is a scalable protocol suitable for very large networks, and networks of varying size.
30 Jun 1998
TL;DR: It is shown that that FAMA-NCS performs better than ALOHA, CSMA, and all prior proposals based on collision avoidance dialogues (e.g., MACA, MACAW, and IEEE 802.11 DFWMAC) in the presence of hidden terminals.
Abstract: The performance of the FAMA-NCS protocol in ad-hoc networks is analyzed FAMA-NCS (for floor acquisition multiple access with non-persistent carrier sensing) guarantees that a single sender is able to send data packets free of collisions to a given receiver at any given time FAMA-NCS is based on a three-way handshake between the sender and receiver in which the sender uses non-persistent carrier sensing to transmit a request-to-send (RTS) and the receiver sends a clear-to-send (CTS) that lasts much longer than the RTS to serve as a "busy tone" that forces all hidden nodes to back off long enough to allow a collision-free data packet to arrive at the receiver It is shown that that FAMA-NCS performs better than ALOHA, CSMA, and all prior proposals based on collision avoidance dialogues (eg, MACA, MACAW, and IEEE 80211 DFWMAC) in the presence of hidden terminals Simulations experiments are used to confirm the analytical results
Patent•
NEC1
TL;DR: In this paper, a mobile terminal can interconnect to an infrastructure network and an ad hoc network while moving, and the integrated configuration consists of an ad-hoc/ infrastructure network address management means, an ad ad hoc/ infrastructure integration move management mean, an Ad hoc/ infrastructures integration destination address capture means.
Abstract: A mobile terminal and method of controlling the same, each that can integrally move between an infrastructure network and an ad hoc network. The mobile terminal can interconnect to an infrastructure network and an ad hoc network while moving. In an address management process, a connection network identification process, and a destination address capture process which are needed to establish communications with the terminal connected to a network, an infrastructure network connection procedure is integrated with an ad hoc network connection procedure. The integrated configuration consists of an ad hoc/ infrastructure network address management means, an ad hoc/ infrastructure integration move management means, an ad hoc/ infrastructure network integration destination address capture means. In each process, it is identified whether or not the mobile terminal is connected to an ad hoc network or infrastructure network, so that the procedure corresponding to the connected network is used.
TL;DR: It is found that the average mobile host switches between the wired and wireless networks 14 times during the trace and moves within the wireless network five times, concluding that latency is a critical problem in the wirelessnetwork.
Abstract: This paper presents results from an eight-day network packet-trace of MosquitoNet. MosquitoNet allows users of laptop computers to switch seamlessly between a metropolitan-area wireless network and a wired network (10 Mbit/s Ethernet) available in offices and on-campus residences. Results include the amount of user mobility between the wired and wireless networks, the amount of mobility within the wireless network, an examination of application end-to-end delays, and an examination of overall packet loss and reordering in the wireless network. We find that the average mobile host switches between the wired and wireless networks 14 times during the trace and moves within the wireless network five times. Round trip latencies in the wireless network are very high, with a minimum of 0.2 seconds. Even higher end-to-end delays, of up to hundreds of seconds, are due to packet loss and reordering. These delays cause users to change their usage patterns when connected to the wireless network. We conclude that latency is a critical problem in the wireless network.