ABSTRACT: Video Dissemination over Hybrid Cellular and Ad Hoc NetworksWe study the problem of disseminating videos to mobile users by using a hybrid cellular and ad hoc network. In particular, we formulate the problem of optimally choosing the mobile devices that will serve as gateways from the cellular to the ad hoc network, the ad hoc routes from the gateways to individual devices, and the layers to deliver on these ad hoc routes. We develop a Mixed Integer Linear Program (MILP)-based algorithm, called POPT, to solve this optimization problem. Pocket delivers the highest possible video quality and optimization problem that determines: 1) The mobile devices that will serve as gateways and relay video data from the cellular network to the ad hoc network, 2) The multihop ad hoc routes for disseminating video data3) The subsets of video data each mobile device relays to the next hops under capacity constraints. We formulate the optimization problem into a Mixed Integer Linear Program (MILP), and propose an MILP-based algorithm, called POPT, to optimally solve the problem.

We recommend the THS algorithm for video streaming over hybrid cellular and ad hoc networks. Last, we also build a real video dissemination system among multiple Android smart phones over a live cellular network. Via actual experiments, we demonstrate the practicality and efficiency of the proposed THS algorithm. We call it Tree-Based Heuristic Scheduling (THS) algorithm, and it works as follows: We first sort all the transmission units in the W-segment scheduling window in descending order of importance, by layer, segment, and video. We then go through these WL units, and sequentially schedule the transmissions to all mobile devices.EXISTING SYSTEM:

Linear Program (LP)-based algorithm called MTS, for lower time complexity generic ad hoc protocols do not work well in hybrid cellular and WiFi ad hoc networks, and may lead to:1) degraded overall throughput, 2) unfair resource allocation, and 3) low resilience to mobility. They propose two approaches to improve the efficiency of ad hoc protocols. First, the base station can run optimization algorithms for the WiFi ad hoc network, for example, to build optimized routes. Second, mobile devices connected to other access networks can offload traffic from the cellular network to those access networks, so as to avoid network congestion around the base station. DISADVANTAGES:

Existing algorithms achieve at least 10 dB quality improvements and result in up to 80% packet delivery delay reduction.PROPOSED SYSTEM:

We propose a hybrid network, in which each multicast group is either in the cellular in the ad hoc mode. Initially, all multicast groups are in ad hoc mode, and when the bandwidth requirement of a group exceeds the ad hoc network capacity, the base station picks up that group and switches it into the cellular mode. In the ad hoc network, a flooding routing protocol is used to discover neighbors and a heuristic is employed to forward video data. Our work differs from in several aspects: 1) we propose a unified optimization problem that jointly finds the optimal gateway mobile devices, ad hoc routes, and video adaptation, 2) we consider existing cellular base stations that may not natively support multicast, and 3) we employ Variable-Bit-Rate (VBR) streams.

More specifically, we empirically measure the mapping between the node location and link capacity several times, and use the resulting values for capacity estimation. We adopt the video traces of H.264/MPEG4 layered videos from an online video library. The mean bit rate and average video quality for each layer of the considered videos are given in Table 2. In this paper, we report sample simulation results of distributing Crew. However, the proposed formulation and solutions are general and also work for the scenarios where mobile devices watch different videos.

ADVANTAGES:

1. The links into mobile devices on breadth-first trees of transmission units with higher quality improvement values are given higher priorities.2. The links with higher ad hoc link capacities are given higher priorities.3. The links from mobile devices with higher cellular link capacities are given higher priorities.MODULE DESCRIPTION:

SERVER CLIENT MODULE:Client-server computing or networking is a distributed application architecture that partitions tasks or workloads between service providers (servers) and service requesters, called clients. Often clients and servers operate over a computer network on separate hardware. A server machine is a high-performance host that is running one or more server programs which share its resources with clients. A client also shares any of its resources; Clients therefore initiate communication sessions with servers which await (listen to) incoming requests.

WIMAX RELAY NETWORKS:

WiMAX bandwidth allocation schemes in employ multiple loops to examine the performance of the different combinations of recipients, which results in extremely high computational complexity. The bandwidth allocation scheme proposed in this study applies greedy methods to achieve low computational complexity while incorporating the table-consulting mechanisms to avoid redundant bandwidth allocation scheme can efficiently allocate bandwidth while maintaining low computational complexity. WiMAX provide diverse data rates, H.264/SVC allow a video stream to be split into one base layer and multiple enhancement layers. This study assumes that a video can be split into six layers (one base layer and five enhancement layers) corresponding to the six video quality levels a user with the requirements of 64kbit/s 128 kbit/s can be satisfied by receiving the base layer and one enhancement layer.

RESOURCE ALLOCATION:

Our resource allocation model for two-hop WiMAX relay networks consists of one BS, M RSs, and N SSs. For consistency, the BS is regarded as the 0th RS and is denoted by RS0 in the following discussion, while the RSs are denoted by RS1 to RSM.An SS can associate either with the BS or with one of the RSs, and the number of SSs associated with RSm is denoted by Nm. The notation SSm;n represents the nth SS associated with RSm.

CQm represents the channel quality of the link between the BS and RSm while CQm;n represents the channel quality between RSm and SSm;n. Assume that the video streams for the links with lower channel quality should be transmitted by the modulation schemes with higher reliability.VIDEO STREAMING:

Scalable video broadcast/multicast solutions efficiently integrates scalable video coding, 3G broadcast and ad-hoc forwarding to balance the system-wide and video quality of all viewers at 3G cell. In our solution, video is downloading into multiple layers. The base station broadcasts different layers at different rates to cover viewers at different ranges. All viewers are guaranteed to receive the base layer, and viewers closer to the base station can receive more enhancement layers. Using WiMAX Relay Networks connections, viewers far away from the base station can obtain from their neighbors closer to the base station the enhancement layers that they cannot receive directly from the base station. Our solution strikes a good balance between the average and worst-case performance for all viewers in the cell. We design multi-hop relay routing schemes to exploit the broadcast nature of ad-hoc transmissions and eliminate redundant video relays from helpers to their receivers.

QUALITY OPTIMIZATION:

Our channel qualities of these links, BSs and RSs can dynamically adapt the downlink modulation and coding schemes (MCSs) for data transmission. When RSs are deployed at appropriate locations between the BSs and SSs, the end-to-end channel qualities can be improved and the BSs and RSs can adopt high data-rate MCSs. Based on this improvement in data rate, IEEE 802.16j systems can offer higher throughput and serve more users than IEEE 802.16e systems. Based on the performance enhancements above, IEEE 802.16j has the potential to provide real-time video multicast services such as mobile IPTV, live video streaming (e.g., athletic events), and online gaming).

However, the BSs should allocate bandwidth efficiently to support such bandwidth-hungry services while guaranteeing the quality of user experience (QoE). The bandwidth allocation problems in IEEE 802.16j networks are more challenging than those in IEEE 802.16e networks because the BSs allocate bandwidth not only to the SSs, but also to the RSs. Multicasting also complicates the bandwidth allocation problems of these factors, designing an efficient bandwidth allocation scheme for video multicast services.

We have presented various bandwidth allocation approaches for video services in IEEE 802.16e networks (i.e., single-hop WiMAX systems). The approaches in and allocate bandwidth by exploiting the common technology of scalable video coding (SVC) specified in the H.264/SVC standard. The H.264/SVC standard is extended from H.264/AVC, and can further split a video stream into a base layer for providing the basic video quality and multiple enhancement layers for providing better video quality layer by-layer.