Hop-by-Hop Routing in
Wireless Mesh Networks with Bandwidth Guarantees
ABSTRACT:
Wireless Mesh Network (WMN) has become
an important edge network to provide Internet access to remote areas and
wireless connections in a metropolitan scale. In this paper, we study the
problem of identifying the maximum available bandwidth path, a fundamental
issue in supporting quality-of-service in WMNs. Due to interference among
links, bandwidth, a well-known bottleneck metric in wired networks, is neither
concave nor additive in wireless networks. We propose a new path weight which
captures the available path bandwidth information. We formally prove that our
hop-by-hop routing protocol based on the new path weight satisfies the
consistency and loop-freeness requirements. The consistency property guarantees
that each node makes a proper packet forwarding decision, so that a data packet
does traverse over the intended path. Our extensive simulation experiments also
show that our proposed path weight outperforms existing path metrics in
identifying high-throughput paths
EXISTING
SYSTEM:
The path with the maximum available
bandwidth is one of the fundamental issues for supporting QoS in the wireless
mesh networks. The available path bandwidth is defined as the maximum additional
rate a flow can push before saturating its path. Therefore, if the traffic rate
of a new flow on a path is no greater than the available bandwidth of this
path, accepting the new traffic will not violate the bandwidth Guaranteed of
the existing flows. The extensive simulation experiments demonstrate that our
routing protocol outperforms the existing routing protocols for finding the
maximum available bandwidth paths. ETT metric adjusted based on the number of
the interference links and the existing traffic load on the interference links.
IRU is the ETT metric weighted with the number of the interference links, while
CATT extends IRU by considering the effect of packet size and raw data rate on
the links because of the use of multiple channels.
DISADVANTAGE
OF EXISTING SYSTEM:
The traffic rate of a new flow on a path
is no greater than the available bandwidth of this path, accepting the new
traffic will not violate the bandwidth guaranteed. A source identifies a widest
path to a destination; intermediate nodes on the widest path may not make a
consistent packet forwarding decisions by using the traditional
destination-based hop-by-hop packet forwarding mechanism. To avoid loops when
routing tables change is an important but difficult problem, and is outside the
scope. The problem of identifying the maximum available bandwidth Path from a
source to a destination, which is also, called the Maximum Bandwidth Problem
(MBP). MBP is a sub problem of the Bandwidth-Constrained Routing Problem
(BCRP), the problem of identifying a path with at least a given amount of
available bandwidth polynomial-time, because the problem is NP-complete in
nature. Even though we can find the available bandwidth of a given path, it is
not easy to identify a schedule that achieves that bandwidth since the
scheduling.
PROPOSED
SYSTEM:
A new path weight that captures the
concept of available bandwidth. We give the mechanism to compare two paths
based on the new path weight. the widest path, many researchers develop new
path weights, and the path with the minimum/maximum weight is assumed to be the
maximum available bandwidth path. The expected transmission count (ETX) metric.
The bandwidth requirement of a certain
request. The protocol in checks the
local available bandwidth of each node
to determine whether it can satisfy the bandwidth requirement. Some
works consider the TDMA-based MAC model and discuss how to assign the available
time slots on each link for a new flow in order
to satisfy the bandwidth requirement.
The isotonicity property of the proposed path weight allows us to develop a
routing protocol that can identify the maximum bandwidth path from each node to
each destination. In particular, it tells us whether a path is worthwhile to be
advertised, meaning whether a path is a potential subpath of a widest path.
MODULES:
ü Path
Selection
ü Isotonic
Path Weight
ü Table
Construction and Optimality
ü Packet
Forwarding and Consistency
ü Route
Update
MODULES DESCRIPTION:
Path
Selection
We would like to develop a distance-vector based
mechanism. In the traditional distance-vector mechanism, a node only has to
advertise the information of its own best path to its neighbors. Each neighbor
can then identify its own best path. In this module, we mentioned that if a node
only advertises the widest path from its own perspective, its neighbors may not
be able to find the widest path. To illustrate, consider the network where the
number of each link is the available bandwidth on the link.
Isotonic
Path Weight
In this module, we introduce our new isotonic path
weight, also describes how we use the path weight to construct routing tables.
The isotonicity property of a path weight is the necessary and sufficient
condition for developing a routing protocol satisfying the optimality and
consistency requirements. We first describe the definition of isotonicity also
here in this module.
Table
Construction and Optimality
The isotonicity property of the proposed
path weight allows us to develop a routing protocol that can identify the maximum
bandwidth path from each node to each destination. In particular, it tells us
whether a path is worthwhile to be advertised, meaning whether a path is a
potential subpath of a widest path. In our routing protocol, if a node finds a new
nondominated path, it will advertise this path information to its neighbors. We
call the packet carrying the path information the route packet
Packet
Forwarding and Consistency
In a traditional hop-by-hop routing
protocol, a packet carries the destination of the packet, and when a node receives
a packet, it looks up the next hop by the destination only. In our mechanism,
apart from the destination, a packet also carries a Routing Field which specifies
the next four hops the packet should traverse. When a node receives this
packet, it identifies the path based on the information in the Routing Field.
It updates the Routing Field and sends it to the next hop.
Route
Update
After the network accepts a new flow or
releases an existing connection, the local available bandwidth of each node
will change, and thus the widest path from a source to a destination may be
different. When the change of the local available bandwidth of a node is larger
than a threshold (say 10 percent), the node will advertise the new information to
its neighbors. After receiving the new bandwidth information, the available
bandwidth of a path to a destination may be changed. Although the node is
static, the network state information changes very often. Therefore, our
routing protocol applies the route update mechanism.
SYSTEM REQUIREMENTS:
HARDWARE REQUIREMENTS:
•
System
: Pentium IV 2.4 GHz.
•
Hard Disk
: 40 GB.
•
Floppy Drive :
1.44 Mb.
•
Monitor :
15 VGA Colour.
•
Mouse :
Logitech.
•
Ram :
512 Mb.
SOFTWARE REQUIREMENTS:
•
Operating
system : - Windows XP.
•
Coding
Language :
JAVA
REFERENCE:
Ronghui Hou, Member, IEEE, King-Shan
Lui, Senior Member, IEEE, Fred Baker, and Jiandong Li, Senior Member, IEEE, “Hop-by-Hop
Routing in Wireless Mesh Networks with Bandwidth Guarantees”, IEEE TRANSACTIONS ON MOBILE COMPUTING, VOL.
11, NO. 2, FEBRUARY 2012.
