Bracer a distributed broadcast protocol in multi hop cognitive radio ad hoc networks with collision avoidance
1. BRACER: A Distributed Broadcast Protocol in Multi-hop Cognitive
Radio Ad Hoc Networks with Collision Avoidance
Abstract:
Broadcast is an important operation in wireless ad hoc networks where
control information is usually propagated as broadcasts for the realization
of most networking protocols. In traditional ad hoc networks, since the
spectrum availability is uniform, broadcasts are delivered via a common
channel which can be heard by all users in a network. However, in
cognitive radio (CR) ad hoc networks, different unlicensed users may
acquire different available channel sets. This non-uniform spectrum
availability imposes special design challenges for broadcasting in CR ad
hoc networks. In this paper, a fully-distributed BRoAdcast protocol in multi-
hop CognitivE Radio ad hoc networks with collision avoidance, BRACER,
is proposed. In our design, we consider practical scenarios that each
unlicensed user is not assumed to be aware of the global network topology,
the spectrum availability information of other users, and time
synchronization information. By intelligently downsizing the original
available channel set and designing the broadcasting sequences and
scheduling schemes, our proposed broadcast protocol can provide very
high successful broadcast ratio while achieving very short average
broadcast delay. It can also avoid broadcast collisions. To the best of our
2. knowledge, this is the first work that addresses the unique broadcasting
challenges in multi-hop CR ad hoc networks with collision avoidance.
Existing System:
Broadcast is an important operation in ad hoc networks, especially in
distributed multi-hop multi-channel networks. Control information
exchange among nodes, such as channel availability and routing
information, is crucial for the realization of most networking protocols in
an ad hoc network.
This control information is often sent out as network-wide broadcasts,
messages that are sent to all other nodes in a network.
Proposed System:
We introduce the proposed broadcast protocol for multi-hop CR ad hoc
networks, BRACER.
There are three components of the proposed BRACER protocol:
1) The construction of the broadcasting sequences.
2) The distributed broadcast scheduling scheme.
3) The broadcast collision avoidance scheme.
We assume that a time-slotted system is adopted for SUs, where the length
of a time slot is long enough to transmit a broadcast packet. In addition, we
3. assume that the locations of SUs are static. We also assume that each SU
knows the locations of its all 2-hop neighbors. We claim that this is a more
valid assumption than the knowledge of global network topology.
Hardware Requirements:
• System : Pentium IV 2.4 GHz.
• Hard Disk : 40 GB.
• Floppy Drive : 1.44 Mb.
• Monitor : 15 VGA Colour.
• Mouse : Logitech.
• RAM : 256 Mb.
Software Requirements:
• Operating system : - Windows XP.
• Front End : - JSP
• Back End : - SQL Server
Software Requirements:
• Operating system : - Windows XP.
• Front End : - .Net
