Performance Optimizations for Deploying VoIP Services in Mesh Networks

Ganguly, Samrat; Navda, Vishnu; Kim, Kyung‐Tae; Kashyap, Anand; Niculescu, Dragoş; Izmailov, Rauf; Hong, Sangjin; Das, Samir R.

doi:10.1109/jsac.2006.881594

Cited by 99 publications

(96 citation statements)

References 24 publications

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“…More recently, Destination based Aggregation (DA) was proposed where packets that have the same destination are aggregated and unicast to that destination [11], [17]. Previous works have used DA to improve back haul traffic in wireless mesh networks [17].…”

Section: B Packet Aggregationmentioning

confidence: 99%

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Packet aggregation in multi-rate wireless LANs

Majeed

Abu-Ghazaleh

2012

2012 9th Annual IEEE Communications Society Conference on Sensor, Mesh and Ad Hoc Communications and Networks (SECON)

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Abstract-In CSMA networks, there is a significant overhead associated with each packet including header overhead and contention overhead. The high overhead problem is exacerbated because some of these overheads are required to be at the lowest data rate to ensure that all contending nodes can compete fairly. For applications where packets are small, such as Voice over IP (VOIP), this means that a majority of the available transmission time is wasted on overhead. Packet aggregation is one of the techniques that has been proposed to amortize the per-transmission overhead over multiple aggregated packets. However, existing heuristics are limited, often not considering multi-rate wireless MAC, or operation in a WLAN environment. In this paper, we first formulate the problem of optimal aggregation for a multi-rate CSMA MAC protocol and show that it is NP-Hard. We then propose two heuristics that solve the aggregation problem for multi-rate WLANs. The first, which we call Data Rate based Aggregation protocol (DRA), divides packets in the MAC queue into groups based on the data rate they are to be transmitted at. The algorithm aggregates packets in the same group and broadcasts the aggregated frame at the data rate of that group. Empirically, DRA achieves several fold increase in throughput compared to basic aggregation. DRA also achieves up to a 200% increase in the number of VoIP calls supported by a single 802.11g AP compared to using state of the art aggregation protocols. The second heuristic, which we call Data Rate based Aggregation with Selective Demotion (DRA-SD), enables cross data rate aggregation. Through preliminary evaluation, we show that selectively demoting packets can further improve performance.

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Section: B Packet Aggregationmentioning

confidence: 99%

“…Previous works have used DA to improve back haul traffic in wireless mesh networks [17]. DA is also similar to the aggregation mechanism that is part of the 802.11n standard, however, to the best of our knowledge, its use for improving the performance of WLANs has not been investigated.…”

Section: B Packet Aggregationmentioning

confidence: 99%

Packet aggregation in multi-rate wireless LANs

Majeed

Abu-Ghazaleh

2012

2012 9th Annual IEEE Communications Society Conference on Sensor, Mesh and Ad Hoc Communications and Networks (SECON)

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“…We perform experiments in which each flow represents either (i) a large file transfer with TCP, or (ii) a bundle containing a large file transfer with TCP and a VoIP stream. We simulate VoIP streams with G.729 codec characteristics using constant bit rate (CBR) UDP traffic [27]: a stream bit rate of 8 Kb/s with a packet size of 40 bytes each. For toll quality service, VoIP streams should maintain a one-way latency (mouth to ear) of less than 150 ms and a delay jitter of less than 30 ms [28].…”

Section: B Multi-flow Topologiesmentioning

confidence: 99%

“…This is because the 802.11 overhead is better amortized over the larger 1460 byte TCP segments used in our FTP simulations. Various optimizations for reducing this overhead have been discussed in prior work [27]. Cross topology We next consider the cross topology in Fig.…”

Section: B Multi-flow Topologiesmentioning

confidence: 99%

Buffer Sizing in 802.11 Wireless Mesh Networks

Jamshaid

Shihada

Xia

et al. 2011

2011 IEEE Eighth International Conference on Mobile Ad-Hoc and Sensor Systems

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“…see Armenia, 2005). Among those seminal studies, the work by the authors of (Niculescu, 2006) constitutes an important reference for research studies that followed. The authors illustrate some of the main challenges associated with the transmission of VoIP over WMNs and analyze the performance of some practical solutions to cope with these challenges.…”

Section: Voip Over Multi Hop Wlan 331 Background and State Of The Artmentioning

confidence: 99%

Experimental Characterization of VoIP Traffic over IEEE 802.11 Wireless LANs

Dini¹,

Portolés-Comeras²,

Nin-Guerrero³

et al. 2011

VoIP Technologies

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IntroductionVoice over Internet Protocol (VoIP) technology has become a potential alternative to and also a supplement of the traditional telephony systems over the Public Switched Telephone Network (PSTN), providing a versatile, flexible and cost-effective solution to speech communications. VoIP allows the transmission of voice signals from one party to another one digitally, i.e., the analog voice signal is coded into small packets of digital data and sent over a network. The traditional telephone network, PSTN, uses the circuit switching technique, in which the network establishes a dedicated end-to-end connection between two hosts. The resources needed to support the communication between these end systems are reserved for the whole duration of the communication, so as to guarantee a given quality of the communication. The main drawback of circuit switching is its lack of flexibility due to the fact that dedicated circuits are idle during silent periods and thus network resources are wasted during these contemplation periods. Unlike PSTN, VoIP networks use packet switching, which sends digitized voice data packets over the networks using many possible paths. The packets are reassembled at their destination to generate the voice signals. Network resources are not reserved in VoIP networks, i.e. voice packets are sent into the network without reserving any bandwidth. On the one hand this method provides more flexibility to the network but, on the other hand, it suffers from congestions. Voice applications are delay intolerant services, therefore voice quality at the end host is not guaranteed in VoIP networks. Nowadays, the pervasiveness of WLAN networks together with the spread of VoIP capable wireless devices has motivated an extensive use of VoIP applications over WLAN networks. However, the interaction between these two technologies (VoIP and WLAN) is still not well understood and has received much attention from the research community during recent years. When the VoIP communication has to travel through a WLAN link congestion problems are hardened due to the shared nature of radio medium, the error prone channel and the limited bandwidth of the link, which can cause a further degradation of the voice quality.

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Performance Optimizations for Deploying VoIP Services in Mesh Networks

Cited by 99 publications

References 24 publications

Packet aggregation in multi-rate wireless LANs

Packet aggregation in multi-rate wireless LANs

Buffer Sizing in 802.11 Wireless Mesh Networks

Experimental Characterization of VoIP Traffic over IEEE 802.11 Wireless LANs

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