138 J. Glob. Innov. Agric. Soc. Sci., 2014, 2(3): 138-142. ISSN (Online): 2311-3839; ISSN (Print): 2312-5225 DOI: 10.17957/JGIASS/2.3.595 http://www.jgiass.com UNRELIABILITY& INSTABILITY OF WIRELESS LINKS BETWEEN WIRELESS NODES IN MOBILE AD HOC NETWORKS - MANET Jawad Ahmad* 1 , Muhammad Zaman 2 , Maryam Azhar 3 , Arif Nawaz 4 , Sammar Abbas 5 and UmerIdrees 6 Department of Computer Science, University of Agriculture, Faisalabad, Punjab, Pakistan * Corresponding Author’s e.mail: jawadahmad212@gmail.com In this paper, It is discussed that why Mobile Ad Hoc Networks are unreliable and some other issues with link stability between the nodes. Then their current solutions are suggested. On the behalf of the vulnerable nature of the MANET, these vulnerabilities disturb the development of mobile ad hoc networks. On the base of these vulnerabilities it is proved that mobile ad hoc networks are unreliable& instable Networks. While in the other part, the mechanism to reduce the unreliability & instability of the wireless link between the devices discussed. Ended up by suggesting some ideas and the solutions that makes Mobile Ad hoc network reliable and stable links between the nodes. Keywords: MANET, DSR, Limited Energy Supply, Broadcast Storm, Mobile Nodes INTRODUCTION A Mobile Ad hoc Network (MANET) is a type of Computer Networks in which wireless mobile nodes can dynamically change its position and can again self-organize in unstructured random and temporary network topologies. In this type of network there is no permanently fixed infrastructure exists. However some wireless nodes / devices assembled in any shape of topology on a temporary basis to work for a specific area or deployment like emergency rescue and battlefield communication. These networks are specifically suitable for scenario where the deployment of a network infrastructure is either not possible or not cost effective. From last couple of years the development and usage of mobile computing devices growing up rapidly, which includes mobiles, laptops, mobile PCs, Personal Digital Assistants (PDAs) and handheld digital devices. These mobile computing devices have encouraged an innovative revolution in the computing domain. Computing will not rely on the ability provided by the personal computers, and the concept of universal computing occurs and becomes one of the research hotspots in the computer science society. In the universal computing environment, individual users utilize, at the same time, several electronic platforms through which they can access all the required information whenever and wherever they may be. The nature of the universal computing has made it necessary to adopt wireless network as the interconnection method: it is not possible for the universal devices to get wired network link whenever and wherever they need to connect with other universal devices. That’s why; the Mobile Ad Hoc Networks (MANETs) is attracting most attentions from many researchers for advance level research. In spite of the some weaknesses, the uses of Mobile Ad hoc Network is increasing day by day. These networks provide rapid deployment and self-configuration capabilities and have applications in a variety of environments such as battlefields, disaster recovery and environmental monitoring. MANET is available in the daily routine environment such as home, office, etc. Now furthermore, the application growth of MANET is increasing at many platforms of industrial and Government level. ISSUES Due to following facts the wireless links between mobile devices / nodes, MANET are not so much consistent& reliable for communication participants / users in a specific area. 1. Limited energy supply 2. Constantly changing topology due to Mobility of the Nodes 3. Broadcasting Storm Because of the features listed above, the mobile ad hoc networks are more prone to suffer from the malicious behaviors than the traditional wired networks. Therefore, it is necessary to pay more attention on these issues in the mobile ad hoc networks to eliminate these vulnerabilities. Limited Energy Supply: Power management is a serious and sensitive issue specially occurs in wireless mobile ad hoc networks where the energy supply is limited. Due to the mobility of nodes in the ad hoc mobile network, it is common that the nodes in the ad hoc network will reply on battery as their power supply method. While nodes in the wired network do not need to consider the power supply problem because they can get electric power supply from the outlets, which generally mean that their power supply should be approximately infinite; the nodes in the mobile ad hoc network need to consider the restricted battery power,