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The current state of Voice over IP in Wireless Mesh Networks
Mohammad Tariq MeeranPhD. Student
School of Digital TechnologiesTallinn University
17 Feb 20161
Introduction
Problem Statement
Research Questions
Research Method
Literature Review
Progress Made So far
Research Plan
• Information on the Research area, motivation
• Problem area identification
• Focused research questions
• Research design
• The current state of VoIP In WMNs
• Current status of the research
• Plan for the coming two years
Agenda
2
Introduction Mesh network
formation is dynamic, unpredictable and self healing.
Voice traffic transportation requires special care, else the voice quality will degrade
For demonstration of WMNs click here.
3
Source: http://www.protectsys.com.br/en/wp-content/uploads/firetide3.jpg
Introduction (cont.) Researchers are actively working to address
the VoIP performance improvement in WMNs.
There are a number of solutions proposed by researchers to solve this problem,› but still VoIP QoS implementation in WMNs is
problematic [5] [6] [7] [8] We will explore recent research trends,
discoveries and open challenges related to voice quality in WMNs.
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Motivation› WMN is a good solution for delivering critical services
emergency disaster relief
battlefield operations
Frequent mobility
No dependency to an existing communication infrastructure[11]
› WMN is a low cost solution for the rural, urban, public services, commercial services and harsh environments
› VoIP is a critical service
› An acceptable VoIP quality is important to meet the users expectations and to encourage the users for the continuous use of ICT services
› Contributing to the European Union's 5G Vision Private and Public Partnership (5GPPP) and its defined milestones [12]
Introduction (cont.)
5
Introduction (cont.)
6
European Union's 5G Vision Private and Public Partnership (5GPPP)
European Union Commission, "5G Vision PPP," 2015
Introduction (cont.)
7European Union Commission, "5G Vision PPP," 2015
Even the latest improvements in the 802.11s and 802.11n with integrating some of the QoS features have not provided promising results [9].
The reason is that either some of the QoS solutions are not specifically for VoIP or they are not practical to implement and remained a theory or it still needs improvement[10] .
Problem Statement
8
1. Which existing standards, protocols are available, which solutions are proposed by researchers?
2. How these standards, protocols and proposed solutions have approached the problem and how far the problem has been addressed?
3. Are the solutions applicable?4. Which 802.11s QoS feature affects the VoIP
performance in 802.11n?
Research Questions
9
5. Which QoS feature affects which VoIP performance factor?
6. Are the available QoS features effective for VoIP performance improvement in WMNs?
7. Which VoIP QoS factor performance is improved by modifying which 802.11s and 802.11n QoS feature?
Backup plan, if no room for improvement in question 7 then:
8. How the addition of fixed mesh routers improve VoIP QoS?
9. Does the IPv6 QoS and mobility features improve VoIP performance?
Research Questions (cont.)
10
Research Problem
Area Selection
Literature Review
Focused Research
Topic
Quantitative(Experime
ntal)Data
Collection
Data Analysis Conclusion
Research Method
11
VoIP QoS measurement Standards› E-model [13] Mean Opinion Score R-Factor
Literature Review
Quality level MOS R-FactorExcellent 4.3-5.0 90-100Very good 4.0-4.3 80-90Good 3.6-4.0 70-80Fair 3.1-3.6 60-70Poor 2.6-3.1 50-60Bad 1.0-2.6 0-50
12
Literature Review (cont.)
13Source: ITU-T E-ModelITU-T, "ITU-T G.107 The E-model: A computational model for use in transmission planning," ITU-T, 2015
Reference connection of the E-modelThe model estimates the conversational quality from mouth to ear as perceived by the user at the receive side, both as listener and talker
Delay› Acceptable limit less than 150ms
Jitter› Acceptable limit less than 100 ms
Packet loss› Acceptable limit less than 5% of whole VoIP
conversation
Literature Review (cont.)
14
Existing Solutions› Standards 802.11e (QoS Standard-2005) [29] 802.11n (New standard with QoS features-
2009) [30] 802.11s (Mesh Standard-2011) [1] 802.11ac (Recent Standard with QoS features-
2013) [31]
Literature Review (cont.)
15
› Other solutions Admission Control Packet Scheduler Traffic scheduler Packet aggregation VoIP Codecs Routing Protocols Priority Schedulers Load-aware mobility management Gateway placement Cognitive Radios And more…
› Discussed in detail in coming slides and covered in the upcoming publication
Literature Review (cont.)
16
Literature Review (cont.)
17
Solution name Advantages Limitations802.11s EDCA, Differentiated service and access categories Not well supported and VoIP performance has not
improved significantlyAdmission Control QoS Channel reservation for multimedia traffic Only solves the problem of access to the medium.Routing Protocols Better usage of resources with reactive routing and
better performance with the proactive routing with thecost of using more resources
Reactive routing is slow, proactive routing is resourcehungry. Slow routing results in excess delay and use ofmore resources consumes lots of device processingpower and battery life.
802.11e EDCA function and good for infrastructure wirelessnetwork
Not developed for WMNs
Codec compression Choice of high quality codec can improve voice quality Codec delay is only one small portion of the wholeproblem and high quality codec increases codec delay andgenerates large VoIP packets
Packet aggregation Avoids redundant packet headers, improves VoIP qualityto some extent in special cases
Packetization and de-packetization delay is added. Takesmore time to route large packets. Packetizing the packetstravelling to different destinations is difficult in the relaynodes
Priority schedulers Improves VoIP performance to some extent In case of continuous flow problem for low prioritypackets and doesn't work well in high load
Load-aware mobility Load balancing of mesh nodes Association phase gets delayed, in high load doesn'tperform good
Gateway placement Improves performance for a limited number of hops andif the nodes are communicating to external nodes
Not specifically for local mesh nodes
TADVO Improves the delay factor using multiple paths andpreferring paths with least amount of delay
Routing adds extra load. Puts route under continuouscomputation process
QoS Aware routing Prefers routes with least amount of load Segmentation and use of several routing protocols addsto network complexity. May not work with high numberof nodes due to multicasting function
SRQA Solves interference issues Only address signal to noise ratioCognitive Radio Helps in admission control process Only solves access to mediumLocal packet recovery Recovering sporadic and link failure packet loss Only addresses packet loss factor
Literature survey completed 1 Paper published in IEEEXplore 2014 4th International
Conference on Wireless Communications, Vehicular Technology, Information Theory and Aerospace & Electronic Systems (VITAE), Aalborg, Denmark
http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=6934413
Simulation tools comparison in progress› New standards and choice of protocols, simulation tools
support of the new standards and protocols has delayed this process. Now we are in the final stage of choosing the simulation tool.
Progress made so far
18
Progress made so far (cont.)
19
2nd Research paper almost ready for submission
Target conference:› The IFIP International Conference: Wireless and
Mobile Networking 2016 (WMNC 2016), France (Submission date 1st March)
Progress made so far (cont.)
20
Progress made so far (cont.)
21
The hypothesis is that the modification and improvement of the QoS features in 802.11s and 802.11n/ac, addition of the fixed-mesh routers/access points and the IPv6 QoS and mobility features will increase the VoIP performance and provide acceptable VoIP QoS metrics.
There will be three main measurement factors that will be taken into consideration in all defined scenarios. › delay› jitter› packet loss
Integrating standards and protocols› 802.11s over 802.11g/n/ac with IPv6 (Decision is based on
the simulation tools capability and support)
Progress made so far (cont.)
22
VoIP-only
with Default QoS
VoIP and non-VoIP with Default
QoS settings
VoIP-only with modified QoS features
VoIP and non-VoIP with modified QoS features
No mobility
Partial Mobility
Fullmobility
Scenarios set 1
Progress made so far (cont.)
23
VoIP-only with Default QoS &
fixed Mesh routers
VoIP and non-VoIP with Default
QoS and fixed mesh routers
VoIP-only with Default QoS and IPv6
VoIP and non-VoIP with IPv6
No mobility
Partial Mobility
Fullmobility
Scenarios set 2:As backup in case scenario set 1 is not promising
Research Plan
24
Research Plan (cont.)
25
[1] IEEE Standards Association. IEEE std 802.11s-2011. IEEE Computer Society. 2011.
[5] A. Malik, J. Qadir, B. Ahmad, K. Alvin Yau and Ubaid Ullah, "QoS in IEEE802.11-based wireless networks:A contemporary review," Journal of Network and Computer Applications, vol. 55, pp. 24, 2015.
[6] J. Yun, J. Han, G. Seong, W. Cho, J. Seo, M. Khan, B. Kim, G. Park, J. Han and K. Han, "Self-organized multi-metric routing for QoS in Wireless mesh networks," in 2014 International Conference on Information Networking (ICOIN) , Phuket, 2014, .
[7] M. Natkaniec, K. Kosek-Szott, S. Szott and G. Bianchi, "A Survey of Medium Access Mechanisms for Providing QoS in Ad-Hoc Networks," IEEE COMMUNICATIONS SURVEYS & TUTORIALS, vol. 15, pp. 592, 2013.
[8] C. Mysirlidis, P. Galiotosy, T. Dagiuklasz and S. Kotsopoulos, "Performance quality evaluation with VoIP traffic aggregation in mobile ad-hoc networks," in Madrid, 2013, pp. 1.
References
26
[9] M. Zogkou, A. Sgora, P. Chatzimisios and D. D. Vergados, "EDCA mechanism and mobility support evaluation in IEEE 802.11s WMNs," in 2014 6th International Congress on Ultra Modern Telecommunications and Control Systems and Workshops (ICUMT), St. Petersburg, 2014, pp. 204.
[10] K. Nisar, A. Amphawan, S. Hassan and N. Sarkar I., "A comprehensive Survey on scheduler for VoIP over WLAN," Network and Computer Applications, vol. 36, pp. 933, 2013.
[11] P. I. Basarkod and S. S. Manvi, "Mobility and QoS aware anycast routing in Mobile ad hoc Networks," Computers and Electrical Engineering, vol. 48, 2015.
[12] European Union Commission, "5G Vision PPP," 2015. [13] ITU-T, "ITU-T G.107 The E-model: A computational model for use in
transmission planning," ITU-T, 2015. [29] LAN/MAN Standards Committee, "IEEE std 802.11e -2005," IEEE,
New York, 2005. [30] IEEE Standards Association, "IEEE std 802.11n," IEEE, 2009. [31] IEEE Standards Association, "IEEE std 802.11ac," IEEE, New York,
2013.
References (cont.)
27
Thank you!Q & A
28