When it comes to Ad-hoc networking, a lot of interest is raised which makes it a significant area of research. For transporting data over a diversity of environments, an adaptable and flexible infrastructure is provided by networks of Wireless Ad hoc. Due to the high visibility and usage of multimedia applications, transmission of video data and real-time audio has increased. Maintaining the quality and caliber of multimedia streams after passing through a network of wireless ad hoc is one of the biggest hurdles. The adaption of network architecture to QoS requirements of multimedia is needed by it. This paper focuses on proposing a unique way or architecture for managing and organizing ad hoc networks which are cluster-based to offer various multimedia streams. Wireless topology of the network is adapted by the presented architecture for improving the caliber of video and audio transmissions. For achieving this goal, some specific information like a capacity of each node and parameters of QoS (packet loss, jitter, delay, and bandwidth) is used by the architecture. The architecture splits the network into clusters which are specialized in specific multimedia traffic. Its feasibility will be demonstrated at the end when performance study of the system will be provided.

Keywords: Cluster-based, topology, QoS, Adapt, QoE

I.     Introduction of A Multimedia Wireless Ad Hoc Cluster Architecture

The formation of networks of a wireless ad hoc compromise of distributed nodes in a set within a bound geographic region. Normally, mobility of nodes, time of nodes, placement or alignment of nodes, and density of nodes give the physical topology. With the use of ad hoc sharing or communication, wireless nodes can exchange without relying on an infrastructure which is wired. Logical topology of the network and lines which data follow are determined by the organization of their physical topology and their communication with some other nodes [1]. With the creation of logical topology, end nodes can exchange information as they have the necessary infrastructure for transporting. Data gathering, remote management, monitoring, and so on are allowed with this infrastructure. Actually, logical topologies’ number depends on algorithms and the criteria which nodes follow [2]. Features of network traffic should be taken into account with the aim of improving transmissions’ efficiency and performance.

In networks of ad hoc, architectures which are cluster-based are quite common. Nodes are organized in tiny groups that perform autonomously and independently by such architectures [3]. In each and every cluster, nodes can commune with others and establish a whole neighborhood. They can also exchange through such neighborhoods established by their neighbors. Meanwhile, communication among clusters is also possible and a cluster can exchange with an external network using a high hierarchical standard. Such a standard is shared among all other clusters [4]. Many schemes and clustering algorithms can be found in studies related with wireless ad hoc. While creating the cluster, the network topology relies on selection criteria of the neighbor. Additionally, topology is changed continuously with the nodes’ motion. Due to it, the number of messages and management increases [5]. In various structures of network, selection of neighbor node has been broadly studied. Considering the aim, the organization of nodes can occur with geographic distance [4], lower consumption of energy [7], lower time of convergence, high bandwidth for transmissions, tolerance of faults or purposes of load distribution, and so on in account.

With the rapid development and growth of wireless methods and technologies, the popularity of networks of wireless ad hoc has become common among people. Various new environments and emergent features along with applications are to be utilized. Actually, new methods are service-oriented and user-oriented networks of wireless ad hoc [8] while the key players are video streaming and real-time audio (their utilization, however, is either too complex or expensive in other networks).

For delivering traffic of real time data in a network of wireless ad hoc, it is quite important to measure and quantify parameters of QoS: guaranteed bandwidth, lost packets, jitter, and delay [9]. From two points of view which are complementary, analysis of QoS should take place. Meanwhile, parameters of QoS should be bound in a specific limit along the period of time for every single multimedia stream. Various streams of multimedia depending on used codec, video, and audio will have several ranges and QoS values.

Sure, attention is paid to managing the flow of traffic in a network but countless researchers take QoS elements [10] when it comes to their proposals [11].  For building logical topology, the present systems of cluster don’t use QoS parameters. Thus, the achieved values of QoS could be found out of the necessary range. That is why, the multimedia communications’ quality will not be actually guaranteed and QoE or quality of experience will be impacted. Additionally, the monitoring of parameters of QoS should be continuous as their values are always changing with the changing of network (data streams, video, new audio which are concurrent, node leavings and joining).

A new architecture for building clusters of wireless ad hoc on the basis of criterion enveloping QoS parameters is proposed in this paper. With such architecture, network can be structured with aspects like nodes’ capacity, streams’ number that has passed from the network, and multimedia streaming in account. Such features actually belong to the network. For each and every multimedia stream, the focus in upon offering a differentiated and guaranteed service for optimizing the exchange among nodes while benefitting from bandwidth which is available and guaranteeing packet loss standards, hitter, and necessary delay.

II.    Literature Review of A Multimedia Wireless Ad Hoc Cluster Architecture

Recently, both the interest and the research have increased on multimedia distribution in terms of networks of ad hoc. Actually, it has occurred due to the hardware capabilities’ improvement and the introduction of new services regarding multimedia. For supporting applications concerning real-time multimedia, it is important to take QoS limitations into consideration.

Zhang et al. considers protocols of MAC and proposes several improvements for solving critical issues such as the wireless medium’s broadcast nature in networks, bandwidth’s bound wireless channel, and video traffic’s stringent QoS requirements. The duo of issue evading strategies were proposed by authors for contention and reservation interleaved systems that are wireless. The video packets which are being sent through channel access on the basis of reservation or contention; they are placed in a set of two buffers after being separated with the utilization of a dual buffer. Taking interactions of contention and reservation periods into consideration, analytical models were developed by authors. The focus of performance tests was directly upon access which was contention-based. It was showed by simulation results that the back off plan promises an increment in throughput with the large number of fixed or reserved periods in every single super frame. While sending video streams of MPEG-4, results were again checked by authors. The hybrid approach which was proposed with the duo of buffering architectures, a better performance was provided by it mostly due to a decreased contention level and increased reservation utilization.

For generating traffic frames of video, a model regarding video traffic was used by Mehta and Narmawala [1]. In both broadcast and multicast scenarios and in lossy networks of wireless ad hoc, it was observed by them that network coding performed quite well. Even in networks of wireless ad hoc with nodes’ low density, network coding performed well with the use of scheme concerning their transmission of multicopy packet. Considering their work, a packet is encoded by a sender node using a type of network coding which is RLNC or random linear network coding with MGM or multigenerational mixing with the goal of providing safety to I frames (MPEG 4’s intraframe video traffic) for minimizing the multiplicative loss through incurring transmission’s delay. Packet delivery is increased while the rate of packet drop is decreased of the multimedia transmission over networks of wireless ad hoc.

Routine protocols are the ones which carry the main weight of maintaining an optimum path and quick multimedia for streams. So, routine protocols have been studied by many authors for understanding authentic features for offering QoS. Furthermore, routing protocols which are QoS-aware, they have been produced by various authors.

Results attained with the utilization of OPNET software, they are analyzed by Al Turki and Mehmood [1]. In the field of ad hoc network, main challenges along with the literature for QoS were surveyed by them. The performance of applications regarding video streaming was evaluated by them with the focus on ad hoc network through simulating 5 various routing elements. Through a middle sized network, multimedia applications can be supported as shown by the results.

Video streaming can be supported with networks of ad hoc and it was demonstrated by Jamali et al. demonstrated in [1]. For doing such, routine protocols were analyzed by them by simulations in the environment of OPNET in terms of QoS and multimedia. For multimedia streaming, GRP, TORA, OLSR, DSR, and AODV were analyzed in their study. Networks can have a good quality of video streaming according to their results. It was concluded that network topology and more QoS requirements made it tough to design a multimedia network of ad hoc.

In [1], a model on the basis of QoS a routing criterion for IEEE 802.11 network of ad hoc was presented by Abdrabou and Zhuang. The proposal is schemed on the basis of design approach of the cross-layer. The proposed scheme actually chooses routes on the basis of a geographical routing protocol of ad hoc and ensures the network resources’ presence through link-layer channel and a traffic source modeling. IEEE 802.11node interactions and features are considered as well by the system. It is checked by the protocol if the selected route has the power of admitting traffic flows without affecting others. Results of simulation show that when it comes to resource utilization, the proposal is quite effective while harnessing a low overhead.

A routing scheme was proposed by Taing et al. [1] that selected shortest paths for multimedia services using a power standard. This is done because of sensitivity of delay to traffic. And for a traffic regarding nonreal time, smaller power standard is used. It is concluded by them mean number of hops for multimedia with the ones of non-real time is given by their proposal. Due to it, multimedia traffic’s transmission delay can be lowered. For multimedia traffic, a higher throughput can be provided by their proposal.

For networks of wireless ad hoc, a multimedia-oriented protocol and architecture was presented in [1]. The services which nodes offer, they are taken into account in a network of ad hoc for selecting the best provider node at the layer of application. A new protocol was designed along with an authentic decision algorithm for providing the best QoS and QoE in terms of multimedia to end users who have participated in network of ad hoc.

In relative literature, ad hoc architecture on the basis of cluster was not found in terms of multimedia.

III.   Cluster-based architecture of A Multimedia Wireless Ad Hoc Cluster Architecture

For building clusters with a guaranteed service in terms of multimedia streaming, the presented architecture is detailed in this section. First of all, initial state will be described which will become the starting point. Moving on, MIP or multimedia init profile will be defined that gathers information regarding multimedia. And then, system processes will be detailed for a valid operation. The last one is estimating the convenient routes for communications in terms of multimedia through the cluster using a routine algorithm.

a.                   Init Profile Multimedia

Consider MIP a data structure representing streams of multimedia through a cluster to a specific node from a source. A single array is contained in an MIP with all the necessary information for deciding a route. Even the information regarding QoS is contained in it which has to been guaranteed by a node for transmitting a stream. Capacity and topological aspects of nodes in the network will evaluate the most eligible nodes and MIP’s properties present to be chosen as the primary configuration. The architecture on the basis of cluster utilized MIP as the key player for building clusters. In the same cluster, it is grouped while MIP with the same nodes under the area which was covered. For each specific case, an MIP’s definition can be adapted.

b.                  System process

For designing architecture, 4 basic methods and processes are proposed that correspond to a node’s basic functions within a network. Transitions and specific states in sets are associated with every process. They will be detailed with the explanation of system state. The relationship among processes is showed in Figure 1. The end and the beginning both compromise process of Init/disconnect. User intervention is required in this process for the execution.

IV.   Routing Algorithm of A Multimedia Wireless Ad Hoc Cluster Architecture

Multimedia connection is requested with a node of cluster. It is referred as SN or source node. The user can perform this request through a user interface in terms of graphics. Multimedia connection is actually the TN or target node which will process streams of multimedia.

Each node has a table of neighbors which is maintained after the creation through the adjacent methods. Moreover, the topology regarding cluster database is created through topology information that it gets from its neighbors. With the starting of a multimedia transmission by an SN, bandwidth requirements of multimedia streaming are used by a routing algorithm. Even the nodes’ information within a cluster is used. SN is the one that performs estimations for determining routes and nodes for forwarding multimedia streaming within a cluster.

V.    Conclusion of A Multimedia Wireless Ad Hoc Cluster Architecture

For wireless networks of ad hoc, a new design or architecture has been proposed in this paper. The architecture is formed on the basis of a cluster and utilizes profiles of QoS for optimizing the multimedia traffic. A flexible solution is provided by this architecture with the skill of guaranteeing multimedia communication’s quality over the wireless network of ad hoc. It has the ability of adapting to several configurations regarding the physical network through an efficient selection of MIPs. In this paper, effect of codec specifications and QoS parameters on the cluster’s topology has been shown. Additionally, jitter and delay are severely affected by the cluster diameter.  For building authentic topology, a control mechanism is provided by the proposed design. Moreover, a scheme of resource reservation is used by the system for guaranteeing multimedia streams’ quality.

Some mechanisms will be integrated for rapid modification according node mobility and spatial changes in the future. Additionally, security will be added to communications using confidentiality techniques and authentication integrity. The final goal is all about deploying the architecture that is proposed in a new and real environment for providing streaming of multimedia in wireless networks in terms of sensors.

 References of A Multimedia Wireless Ad Hoc Cluster Architecture