Mesh Uncertain Demand Mini Report

7/31/2019 Mesh Uncertain Demand Mini Report

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ABSTRACT

Wireless Mesh networks will be dominant in the next-generation wireless networks

with the integration of various wireless access networks. The deployment of various wireless

technologies (2G, 3G, WLAN, WMAN, etc.) in combination with the evolution of Mobile

Terminals (MTs) with multiple network interfaces and the development of IP-based

applications (non-real-time or real-time) has allowed the user to have access to IP services

anywhere at anytime from any network.

Under the circumstances where more data and packets are sent than the capacity and where

the load is not distributed smoothly, i.e. nodes transmits unpredictably, throughput

management and load balancing is essential.

Therefore in this work we first create a wireless mesh network, followed by deploying a

technique for measuring throughput at each node. Throughput is calculated as available

bandwidth at the nodes and is calculated based on packet success rate. We model VBR

(Variable bit rate traffic). If a node is serving more than one session and there is a constraint

at such node than data will be distributed to outgoing sessions equivalently. i.e. those nodes

with higher demand will be restricted, thus ensuring a fairness.


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1. INTRODUCTION

Wireless networking is becoming an increasingly important and popular way to provide

global information access to users on the move. Current technologies vary widely in their

bandwidths, latencies, frequencies, and media access methods. Despite this heterogeneity,

most existing wireless network technologies can be divided into two categories: those that

provide a low-bandwidth service over a wide geographic area and those that provide a high

bandwidth service over a narrow geographic area. Unfortunately, neither technology in and of

itself makes possible the best available network at all times. Wireless local area networks

only provide limited coverage, and a mobile host equipped only with a wide-area data

interface does not have the opportunity to take advantage of existing high-bandwidth

infrastructure such as in-building RF networks or wired networks. No single network

technology simultaneously provides a low-latency, high-bandwidth, wide-area connection to

a large number of users simultaneous.

We are trying to find the solution to the global information access problem is to use a

combination of these wireless networks to provide the best possible coverage and bandwidth

over a variety of geographic ranges in wireless mesh network. A mobile device with multiple

wireless network interfaces has many ways of accessing the wired infrastructure through

alternative wireless subnets. This allows it to overcome the problems of accessing

information in the best possible manner for its current environment.

A wireless mesh network (WMN) is a communications networkmade up

ofradio nodes organized in a mesh topology. Wireless mesh networks often consist of mesh

clients, mesh routers and gateways. The mesh clients are often laptops, cell phones and other

wireless devices while the mesh routers forward traffic to and from the gateways which may,

but need not, connect to the Internet. The coverage area of the radio nodes working as a

single network is sometimes called a mesh cloud. Access to this mesh cloud is dependent on

the radio nodes working in harmony with each other to create a radio network. A mesh

network is reliable and offers redundancy. When one node can no longer operate, the rest ofthe nodes can still communicate with each other, directly or through one or more intermediate
http://en.wikipedia.org/wiki/Telecommunications_networkhttp://en.wikipedia.org/wiki/Radiohttp://en.wikipedia.org/wiki/Node_(networking)http://en.wikipedia.org/wiki/Mesh_networkinghttp://en.wikipedia.org/wiki/Network_topologyhttp://en.wikipedia.org/wiki/Mesh_nodehttp://en.wikipedia.org/wiki/Mesh_nodehttp://en.wikipedia.org/wiki/Network_topologyhttp://en.wikipedia.org/wiki/Mesh_networkinghttp://en.wikipedia.org/wiki/Node_(networking)http://en.wikipedia.org/wiki/Radiohttp://en.wikipedia.org/wiki/Telecommunications_network


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nodes. The animation below illustrates how wireless mesh networks can self form and self

heal. Wireless mesh networks can be implemented with various wireless technology

including 802.11, 802.15, 802.16, cellular technologies or combinations of more than one

type.

A wireless mesh network can be seen as a special type ofwireless ad-hoc network. A

wireless mesh network often has a more planned configuration, and may be deployed to

provide dynamic and cost effective connectivity over a certain geographic area. An ad-hoc

network, on the other hand, is formedad hoc when wireless devices come within

communication range of each other. The mesh routers may be mobile, and be moved

according to specific demands arising in the network. Often the mesh routers are not limited

in terms of resources compared to other nodes in the network and thus can be exploited to

perform more resource intensive functions. In this way, the wireless mesh network differs

from an ad-hoc network, since these nodes are often constrained by resources.

Network structure

Architecture

Wireless mesh architecture is a first step towards providing cost effective and dynamic high-

bandwidth networks over a specific coverage area. Wireless mesh architectures infrastructure

is, in effect, a router network minus the cabling between nodes. It's built of peer radio devices

that don't have to be cabled to a wired port like traditional WLAN access points (AP) do.

Mesh architecture sustains signal strength by breaking long distances into a series of shorter

hops. Intermediate nodes not only boost the signal, but cooperatively make forwarding
http://en.wikipedia.org/wiki/802.11shttp://en.wikipedia.org/wiki/802.15http://en.wikipedia.org/wiki/802.16http://en.wikipedia.org/wiki/Wireless_ad-hoc_networkhttp://en.wikipedia.org/wiki/Ad-hoc_networkhttp://en.wikipedia.org/wiki/Ad-hoc_networkhttp://en.wikipedia.org/wiki/Ad_hochttp://en.wikipedia.org/wiki/Ad_hochttp://en.wikipedia.org/wiki/Ad-hoc_networkhttp://en.wikipedia.org/wiki/Ad-hoc_networkhttp://en.wikipedia.org/wiki/Wireless_ad-hoc_networkhttp://en.wikipedia.org/wiki/802.16http://en.wikipedia.org/wiki/802.15http://en.wikipedia.org/wiki/802.11s


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decisions based on their knowledge of the network, i.e. perform routing. Such an architecture

may with careful design provide high bandwidth, spectral efficiency, and economic

advantage over the coverage area.

Wireless mesh networks have a relatively stable topology except for the occasional failure of

nodes or addition of new nodes. The path of traffic, being aggregated from a large number of

end users, changes infrequently. Practically all the traffic in an infrastructure mesh network is

either forwarded to or from a gateway, while in ad hoc networks or client mesh networks the

traffic flows between arbitrary pairs of nodes.[1]

Management

This type of infrastructure can be decentralized (with no central server) or centrally managed

(with a central server),[2]

both are relatively inexpensive, and very reliable and resilient, as

each nodeneeds only transmit as far as the next node. Nodes act as routers to transmit data

from nearby nodes to peers that are too far away to reach in a single hop, resulting in a

network that can span larger distances. The topology of a mesh network is also reliable, as

each node is connected to several other nodes. If one node drops out of the network, due to

hardware failure or any other reason, its neighbors can quickly find another route using a

routing protocol.

Applications

Mesh networks may involve either fixed or mobile devices. The solutions are as diverse as

communication needs, for example in difficult environments such as emergency situations,

tunnels, oil rigs, battlefield surveillance, high speed mobile video applications on board

public transport or real time racing car telemetry. An important possible application for

wireless mesh networks is VoIP. By using a Quality of Service scheme, the wireless mesh

may support local telephone calls to be routed through the mesh.

Some current applications:

U.S. military forces are now using wireless mesh networking to connect their computers,mainly ruggedized laptops, in field operations.

Electric meters now being deployed on residences transfer their readings from one toanother and eventually to the central office for billing without the need for human meter

readers or the need to connect the meters with cables.[3]
http://en.wikipedia.org/wiki/Wireless_mesh_network#cite_note-jun-0http://en.wikipedia.org/wiki/Wireless_mesh_network#cite_note-jun-0http://en.wikipedia.org/wiki/Wireless_mesh_network#cite_note-jun-0http://en.wikipedia.org/wiki/Wireless_mesh_network#cite_note-chen-1http://en.wikipedia.org/wiki/Wireless_mesh_network#cite_note-chen-1http://en.wikipedia.org/wiki/Wireless_mesh_network#cite_note-chen-1http://en.wikipedia.org/wiki/Node_(networking)http://en.wikipedia.org/wiki/Router_(computing)http://en.wikipedia.org/wiki/Peer-to-peerhttp://en.wikipedia.org/wiki/Mesh_networkinghttp://en.wikipedia.org/wiki/Wireless_mesh_network#cite_note-2http://en.wikipedia.org/wiki/Wireless_mesh_network#cite_note-2http://en.wikipedia.org/wiki/Wireless_mesh_network#cite_note-2http://en.wikipedia.org/wiki/Wireless_mesh_network#cite_note-2http://en.wikipedia.org/wiki/Mesh_networkinghttp://en.wikipedia.org/wiki/Peer-to-peerhttp://en.wikipedia.org/wiki/Router_(computing)http://en.wikipedia.org/wiki/Node_(networking)http://en.wikipedia.org/wiki/Wireless_mesh_network#cite_note-chen-1http://en.wikipedia.org/wiki/Wireless_mesh_network#cite_note-jun-0


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The laptops in the One Laptop per Child program use wireless mesh networking to enablestudents to exchange files and get on the Internet even though they lack wired or cell

phone or other physical connections in their area.

The 66-satellite Iridium constellation operates as a mesh network, with wireless linksbetween adjacent satellites. Calls between two satellite phones are routed through the

mesh, from one satellite to another across the constellation, without having to go through

an earth station. This makes for a smaller travel distance for the signal, reducing latency,

and also allows for the constellation to operate with far fewer earth stations that would be

required for 66 traditional communications satellites.

Operation

The principle is similar to the way packets travel around the wired Internetdata will hop

from one device to another until it reaches its destination. Dynamic routing algorithms

implemented in each device allow this to happen. To implement such dynamic routing

protocols, each device needs to communicate routing information to other devices in the

network. Each device then determines what to do with the data it receiveseither pass it on

to the next device or keep it, depending on the protocol. The routing algorithm used should

attempt to always ensure that the data takes the most appropriate (fastest) route to its

destination.

Multi-radio mesh

Multi-radio mesh refers to a unique pair of dedicated radios on each end of the link. This

means there is a unique frequency used for each wireless hop and thus a

dedicated CSMA collision domain. This is a true mesh link where you can achieve maximum

performance without bandwidth degradation in the mesh and without adding latency. Thus

voice and video applications work just as they would on a wired Ethernet network. In true

802.11 networks, there is no concept of a mesh. There are only Access Points (AP's) and

Stations. A multi-radio wireless mesh node will dedicate one of the radios to act as a station,

and connect to a neighbor node AP radio.

Research topics

One of the more often cited papers on Wireless Mesh Networks identified the following areas

as open research problems in 2005

New modulation scheme
http://en.wikipedia.org/wiki/One_Laptop_per_Childhttp://en.wikipedia.org/wiki/Iridium_satellite_constellationhttp://en.wikipedia.org/wiki/Earth_stationhttp://en.wikipedia.org/wiki/Packet_(information_technology)http://en.wikipedia.org/wiki/Internethttp://en.wikipedia.org/wiki/Routinghttp://en.wikipedia.org/wiki/Algorithmhttp://en.wikipedia.org/wiki/Carrier_sense_multiple_accesshttp://en.wikipedia.org/wiki/Collision_domainhttp://en.wikipedia.org/wiki/Collision_domainhttp://en.wikipedia.org/wiki/Carrier_sense_multiple_accesshttp://en.wikipedia.org/wiki/Algorithmhttp://en.wikipedia.org/wiki/Routinghttp://en.wikipedia.org/wiki/Internethttp://en.wikipedia.org/wiki/Packet_(information_technology)http://en.wikipedia.org/wiki/Earth_stationhttp://en.wikipedia.org/wiki/Iridium_satellite_constellationhttp://en.wikipedia.org/wiki/One_Laptop_per_Child


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In order to achieve higher transmission rate, new wideband transmission schemesother than OFDM and UWB are needed.

Advanced antenna processing Advanced antenna processing including directional, smart and multiple

antenna technologies is further investigated, since their complexity and cost are still

too high for wide commercialization.

Flexible spectrum management Tremendous efforts on research of frequency-agile techniques are being performed

for increased efficiency.

Cross-layer design Cross-layer research is a popular current research topic where information is shared

between different communications layers in order to increase the knowledge and

current state of the network. This could enable new and more efficient protocols to be

developed. A joint protocol which combines various design problems like routing,

scheduling, channel assignment etc. can achieve higher performance since it is

proven that these problems are strongly co-related.[4]It is important to note that

careless cross-layer design could lead to code which is difficult to maintain and

extend.[5]

Protocols

Routing protocols

There are more than 70 competing schemes for routing packets across mesh networks. Some

of these include:

AODV (Ad hoc On-Demand Distance Vector) B.A.T.M.A.N. (Better Approach To Mobile Adhoc Networking) Babel (protocol) (a distance-vector routing protocol for IPv6 and IPv4 with fast

convergence properties)

DNVR (Dynamic NIx-Vector Routing) DSDV (Destination-Sequenced Distance-Vector Routing) DSR (Dynamic Source Routing)
http://en.wikipedia.org/wiki/Orthogonal_frequency-division_multiplexinghttp://en.wikipedia.org/wiki/Ultra-widebandhttp://en.wikipedia.org/wiki/Directional_antennahttp://en.wikipedia.org/wiki/Smart_antennahttp://en.wikipedia.org/wiki/Multiple_antenna_researchhttp://en.wikipedia.org/wiki/Multiple_antenna_researchhttp://en.wikipedia.org/wiki/Spectrum_managementhttp://en.wikipedia.org/wiki/Wireless_mesh_network#cite_note-Pathak-3http://en.wikipedia.org/wiki/Wireless_mesh_network#cite_note-Pathak-3http://en.wikipedia.org/wiki/Wireless_mesh_network#cite_note-Pathak-3http://en.wikipedia.org/wiki/Wireless_mesh_network#cite_note-kawadia-4http://en.wikipedia.org/wiki/Wireless_mesh_network#cite_note-kawadia-4http://en.wikipedia.org/wiki/Wireless_mesh_network#cite_note-kawadia-4http://en.wikipedia.org/wiki/Ad-hoc_On-demand_Distance_Vectorhttp://en.wikipedia.org/wiki/B.A.T.M.A.N.http://en.wikipedia.org/wiki/Babel_(protocol)http://en.wikipedia.org/w/index.php?title=Dynamic_NIx-Vector_Routing&action=edit&redlink=1http://en.wikipedia.org/wiki/DSDVhttp://en.wikipedia.org/wiki/Dynamic_Source_Routinghttp://en.wikipedia.org/wiki/Dynamic_Source_Routinghttp://en.wikipedia.org/wiki/DSDVhttp://en.wikipedia.org/w/index.php?title=Dynamic_NIx-Vector_Routing&action=edit&redlink=1http://en.wikipedia.org/wiki/Babel_(protocol)http://en.wikipedia.org/wiki/B.A.T.M.A.N.http://en.wikipedia.org/wiki/Ad-hoc_On-demand_Distance_Vectorhttp://en.wikipedia.org/wiki/Wireless_mesh_network#cite_note-kawadia-4http://en.wikipedia.org/wiki/Wireless_mesh_network#cite_note-Pathak-3http://en.wikipedia.org/wiki/Spectrum_managementhttp://en.wikipedia.org/wiki/Multiple_antenna_researchhttp://en.wikipedia.org/wiki/Multiple_antenna_researchhttp://en.wikipedia.org/wiki/Smart_antennahttp://en.wikipedia.org/wiki/Directional_antennahttp://en.wikipedia.org/wiki/Ultra-widebandhttp://en.wikipedia.org/wiki/Orthogonal_frequency-division_multiplexing


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HSLS (Hazy-Sighted Link State) HWMP (Hybrid Wireless Mesh Protocol) IWMP (Infrastructure Wireless Mesh Protocol) for Infrastructure Mesh Networks by

GRECO UFPB-Brazil

MRP (Wireless mesh networks routing protocol) by Jangeun Jun and Mihail L. Sichitiu OLSR (Optimized Link State Routing protocol) OORP (OrderOne Routing Protocol) (OrderOne Networks Routing Protocol) OSPF (Open Shortest Path First Routing) PWRP (Predictive Wireless Routing Protocol) TORA (Temporally-Ordered Routing Algorithm) ZRP (Zone Routing Protocol)The IEEE is developing a set of standards under the title 802.11s to define an architecture and

protocol for ESS Mesh Networking.

A more thorough list can be found at Ad hoc routing protocol list.

Autoconfiguration protocols

Standard autoconfiguration protocols, such as DHCP or IPv6 stateless autoconfiguration may

be used over mesh networks.

Mesh network specific autoconfiguration protocols include:

Ad-Hoc Configuration Protocol (AHCP) Proactive Autoconfiguration (Proactive Autoconfiguration Protocol) Dynamic WMN Configuration Protocol (DWCP)
http://en.wikipedia.org/wiki/Hazy_Sighted_Link_State_Routing_Protocolhttp://en.wikipedia.org/wiki/Hybrid_Wireless_Mesh_Protocolhttp://en.wikipedia.org/wiki/Infrastructure_Wireless_Mesh_Protocolhttp://en.wikipedia.org/wiki/MRPhttp://en.wikipedia.org/wiki/Optimized_link_state_routing_protocolhttp://en.wikipedia.org/wiki/Order_One_Network_Protocolhttp://en.wikipedia.org/wiki/Open_Shortest_Path_Firsthttp://en.wikipedia.org/w/index.php?title=PWRP&action=edit&redlink=1http://en.wikipedia.org/wiki/Temporally-ordered_routing_algorithmhttp://en.wikipedia.org/wiki/Zone_Routing_Protocolhttp://en.wikipedia.org/wiki/IEEEhttp://en.wikipedia.org/wiki/IEEE_802.11shttp://en.wikipedia.org/wiki/Mesh_Networkinghttp://en.wikipedia.org/wiki/Ad_hoc_routing_protocol_listhttp://en.wikipedia.org/wiki/DHCPhttp://en.wikipedia.org/wiki/IPv6#Stateless_address_autoconfigurationhttp://en.wikipedia.org/w/index.php?title=Proactive_Autoconfiguration_Protocol&action=edit&redlink=1http://en.wikipedia.org/w/index.php?title=Proactive_Autoconfiguration_Protocol&action=edit&redlink=1http://en.wikipedia.org/wiki/IPv6#Stateless_address_autoconfigurationhttp://en.wikipedia.org/wiki/DHCPhttp://en.wikipedia.org/wiki/Ad_hoc_routing_protocol_listhttp://en.wikipedia.org/wiki/Mesh_Networkinghttp://en.wikipedia.org/wiki/IEEE_802.11shttp://en.wikipedia.org/wiki/IEEEhttp://en.wikipedia.org/wiki/Zone_Routing_Protocolhttp://en.wikipedia.org/wiki/Temporally-ordered_routing_algorithmhttp://en.wikipedia.org/w/index.php?title=PWRP&action=edit&redlink=1http://en.wikipedia.org/wiki/Open_Shortest_Path_Firsthttp://en.wikipedia.org/wiki/Order_One_Network_Protocolhttp://en.wikipedia.org/wiki/Optimized_link_state_routing_protocolhttp://en.wikipedia.org/wiki/MRPhttp://en.wikipedia.org/wiki/Infrastructure_Wireless_Mesh_Protocolhttp://en.wikipedia.org/wiki/Hybrid_Wireless_Mesh_Protocolhttp://en.wikipedia.org/wiki/Hazy_Sighted_Link_State_Routing_Protocol


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3. PROBLEM STATEMENT

Open issue How to achieve optimal routing under the high dynamic and uncertain traffic

in WMN

Our contributions Characterize the traffic demand uncertainty using statistic methods Integrate traffic uncertainty into optimal network routing

4. OBJECTIVE

The concept of a mesh network architecture is being adopted increasingly in the field in the

development and deployment of new networks or in the replacement, migration, or evolution

of existing networks. In a generic mesh network, a set of nodes is interconnected with links

following an arbitrary topology. The routes of end-to-end paths over the links can be

arbitrary.

In such a network, path structure is hybrid and the routes passes through other nodes. Due to

lack of control over the topology or expansion of such networks, ensuring low drop under

high and unpredicatable traffic is difficult. Therefore the objective is to design a suitable

technique for calculating the throughput at the nodes, followed by a statistical technique to

analyze which routes have high demand and if the demand is unvaiable to attain. Then the

nodes adopts rate limiting or enhancement to meet the demand at the same time ensuring

fairness.


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4. Methodology


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Initially routes are calculated without considering any throughput or other factors, assuming

that the nodes can meet the routing and transmission criteria. Once data transmission starts,

nodes gather the traffic information.

Now once the uncertain demand comes, the objective is to minimize packet drop and latency.Hence it is a problem of linear programming. Therefore we introduce a linear programming

with following criteria.

Goal: Maximize (Scaling factor) Constraints

Fairness constraint Each flow must be no less than df

Congestion constraint Interference sets capacities

Node radio constraintThe number of radios at each node

Dual Formulation Goal: Minimize the overall price of all interference sets Constraints

The aggregated edge and node prices should be greater than the flowprice

Weighted flow price over its demand must be at least 1


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The process can be summarized with following theory


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Related work

In [1] it provides the impact of Both provisioning new connections and restoring existing

connections after a Failure require paths to be set up. Until recently this has been done using

a centralized approach: A centralized server (e.g., a Network Management System -NMS)

maintains a view of the entire network and is responsible for selecting paths and sending

commands to the XCs to establish the connections. However, there is currently a trend

towards distributed control in which XCs implement a distributed control plane.

The distributed approach typically distributes only routing information,When

blocking occurs, the signalling setup request cranks-back to the source node to try an

alternative path, which increases the total restoration time. The centralized restoration path

server could optimize restoration path selection.

In [2] We consider dynamic traffic where a pair of link-disjoint primary and backup paths is

provisioned when a new connection request arrives. After a failure occurs, the affected

connections switch traffic from their primary paths to backup paths. To protect against next

potential failure, we reprovision new backups for connections that become unprotected or

vulnerable because of losing their primary or their backup due to the previous failure or

due to backup resource sharing. This approach is called Minimal Backup Reprovisioning

(MBR). An alternative approach is to globally rearrange backups for all connections after one

failure occurs, which is called Global Backup Reprovisioning (GBR).In aprotection scheme,

extra bandwidth is reserved when the connection is provisioned. Usually, a pair of paths is

provided to a connection: one is used to carry traffic during normal operation, referred to as

theprimary path, and the other path, referred to as the backup path, is reserved and will be

activated after a failure occurs on the primary path. The primary and backup paths are usually


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link or node disjoint, which guarantees that at least one path is available when any single link

or node (except the two end nodes) fails in the network. The backup resources are usually

provisioned and reserved when primary resources are provisioned and established, and torn

down when the connection leaves the network.

In [3] WMN backbone routers use multihop communication similarly to ad hoc networks On

the other hand, mobile users connect to the backbone via mesh routers that play the role of

access points. The backbone routers typically are stationary, which permits routing metrics to

model link quality instead of simply using the number of hops. Assuming that the common-

case application in WMNs is Internet access, traffic is concentrated on links close to the

gateways Wireless mesh networks (WMNs) aim at guaranteeing connectivity. WMNs build a

multihop wireless backbone to interconnect isolated local area networks (LANs) and to

extend backhaul access to users not within range of typical access points. Backbone routers

are usually stationary, and mobile users roam among them.

In[4] we study Resilience is the capability of recovering from network component failures.

the MPLS/GMPLS recovery mechanism which can be roughly classified into the following

two techniques: protection and rerouting. In protection switching, often called fast reroute,

the alternate LSP paths are preprovisioned to minimize the disruption of the service in case

the network component fails. In the rerouting scheme, the recovery LSP paths are established

after failures occur.

In [5] we study The capability of fault-tolerant provisioning is also referred to as resilience,

and can be characterized by multiple metrics such as availability .The huge transmission

capability of optical backbone networks requires fault-tolerant provisioning, which can be

achieved using various techniques to recover disrupted traffic by a network failure. In

connection-based WDM opticalnetworks, resilience is usually realized by protection, i.e.,

pre-selecting a set of resources to establish a backup path for a working path.


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Software requirement specification

Hardware Requirement

Pentium core 2 due or above with 1.8Ghz and above

4 GB RAM

Software Requirement

Windows 7 32/64 bit, Omnetpp3.3p2, Visual Studio.Net 2008, Excell-2007


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System Design

Detailed Algorithm1. Mesh Network Formation:

We develop mesh network by combining Static GSM network with bases stations with

enough power to serve the mobiles and it's GSM mobiles which can communicate through

the base stations as well as can get connected to wifi Network where the wifi router is

connected with the GSM base station. Thus satisfying the first criteria of forming

unidirectional links which includes both static as well as dynamic link.

2. Throughput Measurement:

The concept of rerouting and service restoration is presented with the help of Bandwidth. We

calculate Bandwidth as link bandwidth.

B=1*b/T where T is the time interval for a packet to arrive at node 2 from node 1 and b is the

number of bits in the packet. Initially all the link bandwidth are initiated to 11.2 Mbps.

3.Throughput Updation:

As nodes keep serving the other nodes, packets are first put in the queue before sending to

routing layer. As the Queue grows, delay also increases which decrease the bandwidth. Thus

Bcircuit(t) is noting but sum(Bcircuit(x,t) )

where x are every node in a circuit or path. C is the link capacity =11.2 Mbps.

4. Storing the Initial Routing condition P(0)

To store the initial routing condition, each node transmits it's bandwidth information with the

route request packet and the total bandwidth with put in route reply which is updated by the

source node.

5. Getting Set of paths i, where i=1,2,...n

We use node disjoint multipath routing for path formation. Hence all the paths i are avilable

at source sorted by P(i).

6. Failure Estimation:

All the nodes periodically exchanges beacon packet. Beside physical layer senses the power

for each packet. Once a node realize that it gets signal from more than one node and signal

source from other node is better than the current node, it estimates that there might be an

failure event. So it adopts either scheduling or rate limiting.


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Sequence Diagram


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Present System

Most of the current routing and transmission protocol for wireless mess network expects the

nodes to be homogeneous and that the traffic demand is equivalent. But consider a small Wifi

home mesh network where modem is connected with a Laptop which is acting linke internet

gateway. Two laptops, one mobile and one tablets are connected to such a network and are

performing various task. In one of the laptops, user is checking his mail, the other laptop, user

is streaming songs from a shared drive of another device. The tablet user is checking youtube

video. Hence the demand for bandwidth and throughput are not same. It is called variable bit

rate traffic. It is obvious that tablet user needs more bandwidth. But with current system, he

will not be able to watch videos because routing will treat this device equal to the device

which is accessing email. Thus we can say that current protocol is not build to serve unequal

traffic demand.

Proposed System

To overcome the limitation of the present system, we will use proposed system. The system

initially behaves as small Wifi mesh network with CBR traffic and finds the routes

accordingly. As data transmission continues, the nodes gathers bandwidth and throughput

information for every flow and session that passes through these nodes. Based on these

information, it runs a statistical check and finds a optimal solution for transmission;

Then it schedules the packets, offers various rates to the sessions based on the solution to

overcome the congestion problem.


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Conclusion

The project is simulated in Omnet++. We first design a system without proposed

optimization scheme. We measure the throughput and latency of such system by passing

VBR traffic through that network. It should show low PDR.

Then we must build proposed method with optimization and result should be better than the

present system.

REFERENCES

1) Fang YuImproving Restoration Success in Mesh Optical Networks.2)Jing Zhang Backup Reprovisioning to Remedy the Effect of Multiple Link

Failures in WDM Mesh Networks

3)Miguel Elias Routing Metrics and Protocols for Wireless Mesh Networks4)Jong Tae ParkDynamic Path Management with Resilience Constraints

under Multiple Link Failures in MPLS/GMPLSNetworks

5)Ming XiaA Novel SLA Framework for Time-DifferentiatedResilience in Optical Mesh Networks


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Mesh Uncertain Demand Mini Report

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