Optimal Multicast Capacity and Delay Tradeoffs
In MANETs
ABSTRACT
In this paper, we give a global perspective of multicast capacity and delay analysis in Mobile Ad Hoc Networks (MANETs). Specifically, we consider four node mobility models:
1. Two-dimensional mobility,
2. Two-dimensional hybrid random walk,
3. One-dimensional mobility, and
4. One-dimensional hybrid random walk.
Two mobility time-scales are investigated in this paper:
· Fast mobility where node mobility is at the same time-scale as data transmissions;
· Slow mobility where node mobility is assumed to occur at a much slower time-scale than data transmissions. Given a delay constraint D, we first characterize the optimal multicast capacity for each of the eight types of mobility models, and then we develop a scheme that can achieve a capacity-delay tradeoff close to the upper bound up to a logarithmic factor. In addition, we also study heterogeneous networks with infrastructure support.
ARCHITECTURE
EXISTING SYSTEM
In Existing System, A single session cannot make full use of the network capacity due to the overhead of the root in the spanning tree. The second difference is the definition of throughput. In multicast scheme, all the k destinations in a session receive the same packet, and only one packet can be treated as valid and the other k Θ (1) packets are redundancies. Search the optimal capacity delay tradeoff and identify the limiting factors of the existing scheduling schemes in MANETs.
Disadvantage:
´ Limiting factors
´ Low redundancy.
PROPOSED SYSTEM
In Proposed System, assume that at each time slot, bits can be transmitted in a successful transmission. Mobility time scales: Two time scales of mobility are considered in this paper:
Fast mobility: The mobility of nodes is at the same time scale as the transmission of packets, i.e., in each time-slot, only one transmission is allowed.
Slow mobility: The mobility of nodes is much slower than the transmission of packets, i.e., multiple transmissions may happen within one time-slot.
ADVANTAGE
ü The advantage of dimensional mobility lies in the fact that it is simple and easily predictable, thus increasing the inter contact rate.
ü Though nodes are limited to only moving horizontally or vertically, the mobility range on their orbit lines is not restricted.
Algorithm – Joint/Scheduling algorithm
In this algorithm, there are two types of transmissions:
1. Source-Relay(S-R) transmission and
2. Relay-Destination(R-D) transmission. Thus, when a particularly pair is selected, there will be two conditions: S-R pair or R-D pair.
1. If node Nsend contains packet P in its relaying pool to be sent to Nreceive, and Nsend is in the same cell as Nreceive, we call Nsend and Nreceive a R-D pair.
2. If node Nsend does not contain packet P in its relaying pool to be sent to Nreceive, while node Nreceive does not contain packet P in its relaying pool to be sent to Nsend, and Nsend is in the same cell as Nreceive, we call Nsend and Nreceive a S-R pair.
MODULES
1. SCHEDULING POLICIES
2. HETEROGENEOUS NETWORKS
3. TRANSMISSION INFRASTRUCTURE
MODULES DESCRIPTION
SCHEDULING POLICIES
In this Module, the information about the current and past status of the network, and can schedule any radio transmission in the current and future time slots, similar. We say a packet is successfully delivered if and only if all destinations within the multicast session have received the packet. In each time slot, for each packet p that has not been successfully delivered and each of its unreached destinations, the scheduler needs to perform the following two functions:
1. Capture
The scheduler needs to decide whether to deliver packet to destination in the current time slot. If yes, the scheduler then needs to choose one relay node (possibly the source node itself) that has a copy of the packet at the beginning of the timeslot, and schedules radio transmissions to forward this packet to destination within the same timeslot, using possibly multi-hop transmissions. When this happens successfully, we say that the chosen relay node has successfully captured the destination of packet. We call this chosen relay node the last mobile relay for packet and destination. And we call the distance between the last mobile relay and the destination as the capture range.
2. Duplication
For a packet p that has not been successfully delivered, the scheduler needs to decide whether to duplicate packet p to other nodes that does not have the packet at the beginning of the time-slot. The scheduler also needs to decide which nodes to relay from and relay to, and how.
HETEROGENEOUS NETWORKS
In this Module, All transmissions can be carried out either in ad hoc mode or in infrastructure mode. We assume that the base stations have a same transmission bandwidth, denoted for each. The bandwidth for each mobile ad hoc node is denoted. Further, we evenly divide the bandwidth into two parts, one for uplink transmissions and the other for downlink transmissions, so that these different kinds of transmissions will not interfere with each other.
TRANSMISSION INFRASTRUCTURE
In this Module, A transmission in infrastructure mode is carried out in the following steps:
1) Uplink: A mobile node holding packet is selected, and transmits this packet to the nearest base station.
2) Infrastructure relay: Once a base station receives a packet from a mobile node, all the other base stations share this packet immediately, (i.e., the delay is considered to be zero) since all base stations are connected by wires.
3) Downlink: Each base station searches for all the packets needed in its own sub region, and transmit all of them to their destined mobile nodes. At this step, every base station will adopt TDMA schemes to delivered different packets for different multicast sessions.
System Specification
HARDWARE & SOFTWARE REQUIREMENTS:
HARDWARE REQUIREMENTS:
· System : Pentium IV 2.4 GHz.
· Hard Disk : 40 GB.
· Floppy Drive : 1.44 Mb.
· Monitor : 15 VGA Color.
· Mouse : Logitech.
· Ram : 512 MB.
SOFTWARE REQUIREMENTS:
· Operating system : Windows 7 Ultimate (32- bit).
· Coding Language : C#.NET
· Front End : Visual Studio 2010 professional