# Wireless Mesh Networks

How to determine the weight of a link in wireless mesh network and the criteria behind ??

How to determine the weight of a link in wireless mesh network and the criteria behind ??

Tuncay Ercan · Yasar University

first, you need to think about the minimum data rate requirements among different links. Data rate and probable congestion control in different nodes help to assign different weight values. Of course, you need to set up another admission control policy to evaluate your weighting links or at least being capable of dynamically change it

• Osama Al Tameemi added an answer:
Can Toriodal distance measure enhance the simulation accuracy of random graphs and stochastic geometry?

When performing analytical math on random graphs and point processes we usually tend to assume infinite sets, that is in order to enhance the tractability. However in practical systems and simulations we do not have an “infinite” space. A suggested workaround is to use Toroidal distances that convolves the flat simulation map similar to the famous “snakes” game.

Can Toriodal distance measure enhance the simulation accuracy of random graphs?

Is there any other method for counter-effect the edge problem ?

Toroidal distance reference in the Appendix of:

C. Bettstetter, "On the minimum node degree and connectivity of a wireless multihop network," in Proceedings of the 3rd ACM international symposium on Mobile ad hoc networking & computing, 2002, pp. 80-91.

Osama Al Tameemi · University of Central Florida

Edge effect, which refers to the points which lie at the border of ur finite deployment area, can bias the results especially as mentioned for interference, number of neighbors, and transmitted power. I would highly recommend using the  Toroidal distance to by-pass the edge effects.

What is the most energy efficient protocol for Wireless sensor networks?

Energy is most important factor for Wireless sensor networks. A node is connected to the base station through a singlehop or a multihop. Here sleeping and wake-up schemes of different nodes are very important to achieve energy efficiency of the system. A protocol is used for communication between the nodes. So what is the most energy efficient protocol for Wireless sensor networks and how can we use priority and delay terms in designing protocols.

Moshaddique Al Ameen · Kyung Hee University

The answer to your question is not straight forward. By nature MAC protocol depneds on the specific applications. You can refre to  "Energy Saving Mechanisms for MAC Protocols in Wireless Sensor Networks" http://dx.doi.org/10.1155/2010/163413 for some general overview.

Port "1" is inhomogeneously filled within the first 3 mesh cells but I cannot start solver. Can anyone explain why?

Hi

When I was trying to simulate a design with coaxial line feeding in cst software I got the above error and the solver was aborted. The solution given for this error is please modify the mesh line distribution or the geometric model to meet this requirement.

Thank you

Anuraag Misra · Variable Energy Cyclotron Centre

Please modify the mesh line distribution or the geometric model to meet the first 3 cell requirement.

Are there any real differences in Ad-hoc network applications?

Can a member in ad-hoc network act as server and another act as a client of this server?

Are there any restrictions about data forms that exchanged between these networks members? ie.. are these networks dedicated only for file transfer, or can be used for instant messages....?

Vinita Jindal · University of Delhi

Yes any member in ad-hoc network act as server and another act as a client at different times.

And moreover, there is no restrictions about data forms that will be exchanged between these networks members. they can send whatever they want. only things there has to be a path that should exist between source and destination.

• Ali Hassan Sodhro added an answer:
Does anyone have experience with Network Metrics:Throughput, delay and jitter?

As I have calculated Packet Loss Ratio, now want to calculate throughput, delay and jitter in Wireless Body Area Networks (WBAN), can anyone tell me how should I proceed further? Thanks in advance

Ali Hassan Sodhro · Chinese Academy of Sciences

thanks nurul sarkar

Is it possible to integrate an optical & and wireless network with NS-3 or NS-2?

is it possible to integrate optical & and wireless network with NS-3 or NS-2?

Somil Saxena · Eigen Technologies

what properties of PON, you wish to implement in backbone n/w?

• The minimum of energy required to communicate between two nodes (is there a closed form expression)?

In wireless sensor networks, if we know the geometrical distribution process of nodes, can we calculate the expected energy cost to transmit a packet from point (A) to point (B) via other other nodes (routed via other nodes). What would be the least energy required?

mohammad azaharuddin Shaikh · SINGRAULI INSTITUTE OF TECHNICAL EDUCATION

in any network energy is transmitted from one node to another but according to the question,  it depends on the size of the packets and  there flag status of its header, means encoding style, which is to be transmitted as you know the geometric path you can calculate the total energy transmitted.

How can I create a fault tolerant network design without a single point of failure?

What would be some of the approaches I could use in order to ensure a fault tolerant network design without a single point of failure, and which approach would be the best for an enterprise network?

Nyembo Salama · University of Bridgeport

yes, the contribution "Muriel M Edard, Steven S. Lumetta, 'Network Reliability and Fault Tolerance" is highly helpful.

Does anyone have knowledge on the distance between two nodes in sensor networks?

Apart from RSSI, what others parameters could be considered in calculating distance between two nodes. Would be thankful if anyone could recommend few high impact publication in this regard?

Audrey Gendreau · Saint Leo University

Here is a great article on this subject.

How does one find a neighborhood node in a wireless sensor network in Matlab?

I have already created the wsn network and I'm finding the cluster head from that node and now I want to find the neighborhood nodes of cluster head.

Note: Are there any matlab functions to find that?

Chandra Shekhar · Indian Institute of Information Technology Allahabad

I hope, power level will help you.

Does anyone have knowledge on Awk programs?

I am trying to calculate delay in multiple hop wireless networks by using the AWK program from trace file but I have problem. It saves packet send time of last node as send time.

Amal Algedir · University of Detroit Mercy

Thank you , I got code for m trace file

• Mr. Gyanappa Walikar added an answer:
What is the different between pico cell and relay node?
A relay node is used for extending coverage but pico also can be used for that. Pico is used for enhancing the network capacity but a relay node can also be used for that.
Mr. Gyanappa Walikar · Sanjay Ghodawat Group of Institutions

pico cell is an small coverage area which extends from 10-100mtrs and its is an portion of cluster or cellular system... main difference between pico and relay node is whenever service provider want to expand the capacity of a cell they can expand by cell sectoring, splitig, and overlaiding internal to the cellular system but relay node is the external to the cellular system configured to extend the capacity of the cellular system.

What are the advantages and disadvantages of using WMAN for implementing metropolitan area network?
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Abdul Razaque · University of Bridgeport
WMAN enables the users to create wireless connections between multiple locations within a metropolitan area. It connects the multiple office buildings in a city or on a university campus. WMAN does not require high cost of placing fiber or copper cabling and leasing lines. Further, WMAN can work as backups for wired networks.
WMAN uses either infrared light or radio waves to transfer data. WMAN is supported with three different standards.
• 802.16
• HiperMAN
• HiperACCESS
In addition, Back haul and last mile are two fundamental types of WMAN.
The advantage of MWAN for implementing metropolitan area network is its beauty due to less cost than fiber-based Local area networks (LANs) due to several reasons. It is easy to use, extend, exchange or back up prevailing fiber infrastructure within hours, preserving time and money on personnel. It also eradicates leased line costs, fiber trenching cost in laying fiber. Another noteworthy benefit of implementing the WMAN is to bridge the “digital divide” by affording linking communities that have not had the access to wireless internet connections and LAN. Implementing of WMAN allows companies, government agencies, etc. to swiftly increase their internet service into new marketplaces for generating better revenues. From other side, WMAN has security issue because it consists of large area and having problem being hacked the information. A WMAN is merely a bigger WAN track, and thus provides the larger chance for a hacker.
Why is the MORE protocol better than the EXOR protocol?
How are these two protocols used to improve throughput and reliability?
Manoj Yadav · Indian Institute of Technology (Banaras Hindu University) Varanasi
The MORE protocol does not have dependency on MAC layer as other opportunistic routing protocol like ExOR which is dependent on the MAC layer.

For more clear view go through following paper--

Trading Structure for Randomness in Wireless Opportunistic Routing
by Szymon Chachulski, Michael Jennings, Sachin Katti, and Dina Katabi
Can you share a simulation qos-aware mac protocol?
Can somebody help me source a code in the paper "Dynamic duty cycle and adaptive contention window based QoS-MAC protocol for wireless multimedia sensor networks"
Nguyen Van · Max Planck Institute of Colloids and Interfaces
thank you Kishore Kovvali
Have anyone analyzed the performance and usability of NS2, NS3 and OMNET in WMN projects?
I have to decide on a simulator tool for simulating WMN routing metrics and protocols. Any suggestions?
Piotr Owczarek · Poznan University of Technology
Actually, not yet. We have written an article about simulators survey, and in my opinion there are two simulators worth to think about: OMNET and ns3. But at this moment we are still investigating that issue.
Can anyone help me with a java code for 'Security in wireless mesh networks through multicast routing protocols'?
Create 10 nodes, packet moving from source to destination using an optimal path, passing min through 4 nodes. Data about packet moving loss ets
packet moving in a optimal path shuold be visible
Jitendra Verma · Jawaharlal Nehru University
Use Qualnet Simulator
• Sonu Auti asked a question:
How to use libssl or openssl under NS2 framework?
I am doing work on network security and want to simulate the protocol under NS2 framework. Does anyone have an idea of how to embed libssl or openssl in NS2?
• Daniel Robert Franklin added an answer:
How to bridge eth0 and wifi interface over AdHoc mode in openWrt ?
I am trying to enable the multicast of hosted openWrt. I believe that the bridge between the LAN and WAN is the most straightforward way to do so.
Daniel Robert Franklin · University of Technology Sydney
Setting up bridging on OpenWRT is described in detail here:

http://wiki.openwrt.org/doc/uci/network

But the basic idea is to edit the file /etc/config/network, create an entry for your desired bridge (probably something like this, slightly different if you want to use DHCP to assign the address):

config 'interface' 'br0'
option 'type' 'bridge'
option 'ifname' 'eth0 wlan0'
option 'proto' 'static'
option 'dns' '192.168.1.1'
option 'gateway' '192.168.1.1'

I'm assuming you have an entry for the wireless interface (and assuming that it is called wlan0) in /etc/config/wireless. Modify as appropriate.

Then restart by issuing the command

This may not be enough to do what you want - do you need multicast routing etc. as well or just want to multicast to a group within your local network?
Why pacifier cannot be used to address the crying baby problem in streaming application?
Pacifier mainly designed to avoid crying baby problems in wireless mesh network. But it cant address that problem in streaming application. I want to know the reason.
Albert Manfredi · The Boeing Company
According to this paper:

http://conferences.sigcomm.org/co-next/2008/CoNext08_proceedings/StudentWorkshopPapers/5.pdf

Pacifier is proposed for reliable multicast in wireless mesh networks. Pacifier works like this: "The source iteratively sends the batches of a file in a roundrobin fashion, for as many rounds as required, until it has received acknowledgments of receiving all batches from all the receiver."

It sounds to me like a different but equally disruptive problem as encountered with multicasting streaming media over IEEE 802.11 networks. It works sort of. In the case of 802.11, individual receivers can expect high packet loss. With Pacifier, the packet rate is going to be too variable for streaming media applications. It's always difficult to use multicast for streaming media in the best of times, since the source can't optimize for each receiver, and it seems to me that Pacifier just makes the problem worse in a streaming media case. But it seems like a good way to achieve error-free multicasting when timely delivery is not the number one priority.
• Devi Dhurai asked a question:
What algorithms are used to improve throughput in Pacifier?
Which techniques and algorithms are useful?
• Help with routing algorithms in high dynamic topology networks?
I want to model a NGEO satellite constellation with terrestrial networks so i need to know some routing algorithms.
José Ignacio Alvarez-Hamelin · University of Buenos Aires
Routing algorithms depends on the application. In case of satellite constellation you can take advantage of the ciclic change of the topologies. In data networks, as Internet, the problem is bonded different, links can appear or disappear in any time, therefore they are not predictable. If you would know about these protocols, try to search with their names; for instance, to wired networks you have OSPF, RIP, and BGP, and for ad-hoc networks good exponents are AODV, OLSR, BATMAN.
• Frederic Andres asked a question:
Does any data mule reference model exist?
It would be interesting to design a suitable reference model for data mule related to disaster prevention and warning confidence rate.
• Ramesh Kumar asked a question:
Can anyone tell me how to make a wireless mesh network by implementing hybrid wireless mesh routing protocol?
Need help with this..
• Sathish Kumar asked a question:
What techniques are there to improve QoS of cognitive radio in wireless mesh networks?
Can anyone suggest me a technique to improve the QoS by reducing the time to assign the spectrum to secondary users in cognitive radio by overcoming "Integer Linear Programming"?
• Sathish Kumar asked a question:
Can anyone suggest routing issues in cognitive radio based wireless mesh networks?
I am interested in routing schemes.