## 4 Scalable Video Streaming over Wireless Network  
The video adaptation over wireless network experiences the following major challenges:  
* Node Mobility: The nodes in a wireless network are free to move and that leads to disruption in the communication. The node mobility affects the bandwidth availability between the source and receiver. The change in the bandwidth degrades the quality of the communication.
* Routing Overhead: The routing algorithms in the wireless network use the periodic exchange of messages to monitor and manage the routes. These management messages consume network resources, hence decreasing the resource availability for the data transmission. In addition, the frequent update of the route in the wireless environment leads to the dropping of data packets.
* Motion Levels: The movements of an object in the video sequences influence the encoding and decoding of the video data. The increase in the objects' motion lead high bitrate of the video data. Hence, that is also an important parameter that needs to be considered in video communication over a bandwidth-constrained network.
* Estimation of Adaptation Parameters: The estimation of the adaptation parameters considering the latter said dynamic conditions is one of the research challenges.  
This experimental work considers an ad-hoc wireless environment consisting of mobile nodes and forwarders. The routing algorithm considered for the experimentation is Ad-hoc On-Demand Distance Vector (AODV) [34], which is considered to be a stable routing algorithm in the wireless domain.  
AODV is capable of routing both unicast communication and multicast packets. It is an on-demand algorithm; it means that the route between source and destination is created when the source has data or packets to send. The routes established are preserved as long as the source requires them for communication. Furthermore, AODV forms trees that connect multicast group members by removing routing loops. To obtain knowledge of network topology, nodes exchange the HELLO packet and Reply packets. Once the route is established, it starts streaming the video packets. In the wireless domain, nodes are acting as a source, forwarder, and destination; they can read the packets. Hence, it is assumed that each node in the wireless network is acting as MANE.  
The size of the scalable video bit-stream varies with the motion level of the video sequence. Here, we considered three video sequences, which are Honeybee, Jockey, and Bosphorus, which represent high, medium, and low motion, respectively. Figure 4 shows the video dataset that is considered in this work. SVC encodes motion parameters along with the video data, therefore as motion increases in the video, the number of packets that need to be transmitted over the network also increases. When these packets are transmitted over a bandwidth-limited network, the dropping of a packet that has motion parameters adversely affects the decoded video at the receiver. That is the reason that a decision taken at ADE varies with the motion level of video sequences.  
With the above-said methodology, we address the challenges listed in this section. The planned wireless network setup considers the listed network challenges and dynamic conditions. Additionally, we consider the background communications and noises by explicitly creating the communications. These setups make the simulation environment more real-time.