LOCATION BASED PROTOCOL FOR WIRELESS NETWORKS

The current networks such as GPSR have its own limitations such as data transmission delay and node errors. To overcome such problems, new protocols are proposed in various studies. In current study, a location-based protocol for wireless network is proposed by using the MAC interception. The algorithm is such that if best possible node is not possible, the data can be transferred using the second-best possible node thus introducing the intermediary nodes as well in the model. Additionally, based on simulation, the results are compared for the performance of the proposed protocol with two other protocols. The results show that the proposed protocol perform better compare to the other protocols in terms of data transmission efficiency and reliability

Route discovery based on energy-distance aware routing scheme for MANET

Route discovery proses in a Mobile Ad hoc Network (MANET) is challenging due to the limitation of energy at each network node. The energy constraint limits network connection lifetime thus affecting the routing process. Therefore, it is necessary for each node in the network to calculate routing factor in terms of energy and distance in deciding optimal candidate relay nodes needed to forward packets. This study proposes a new route discovery mechanism called the Energy-Distance Routing Aware (EDRA) that determines the selection of nodes during route discovery process to improve the network connection lifetime. This mechanism comprises of three schemes namely the Energy-Distance Factor Aware (EDFA), the Energy-Distance Forward Strategy (EDFS), and the Energy-Aware Route Selection (EARS). The EDFA scheme begins by calculating each nodes energy level (ei) and the distance (di) to the neighbouring nodes to produce the energy-distance factor value used in selecting the relay nodes. Next, the EDFS scheme forwards route request packets within discovery area of relay nodes based on the number of nodes. Then, the EARS scheme selects stable routing path utilising updated status information from EDFA and EDFS. The evaluation of EDRA mechanism is performed using network simulator Ns2 based on a defined set of performance metrics, scenarios and network scalability. The experimental results show that the EDRA gains significant improvement in the network connection lifetime when compared to those of the similar mechanisms, namely the AODV and the DREAM. EDRA also optimises energy consumption by utilising efficient forwarding decisions on varying scale of network nodes. Moreover, EDRA maximizes network connection lifetime while preserving throughput and packet drop ratio. This study contributes toward developing an efficient energy-aware routing to sustain longer network connection lifetime in MANET environment. The contribution is significant in promoting the use of green and sustainable next generation network technology

Subjective logic based trust model for geographic routing in mobile ad hoc networks

Uobičajeni modeli pouzdanosti ne uspijevaju izraziti pojam nesigurnosti tijekom uspostavljanja pouzdanih odnosa između pokretnih čvorova. Nadalje, nedostaje im uvažavanje značajki okoline u ocjeni pouzdanosti. U radu se predlaže model pouzdanosti zasnovan na subjektivnoj logici u POR (SLT-POR) koji u modelu integrira pouzdanost zasnovanu na kontekstu i onu zasnovanu na ponašanju. Pouzdanost zasnovana na ponašanju uključuje fuziju evidencije zasnovane na subjektivnoj logici u evaluaciji indirektne pouzdanosti kako bi se eksplicitno predstavilo i upravljalo neznanjem kao nesigurnošću. Odnos pouzdanosti između čvorova ne može uvijek odražavati stvarni odnos te stoga provedena odluka iz izvedenog odnosa pouzdanosti nije uvijek točna. Teorija subjektivne logike uključuje dinamičkog operatora osnovne brzine koji procjenjuje očekivanje mišljenja i bavi se nesigurnošću u skupljanju podataka. U mjerenju pouzdanost zasnovane na obilježjima konteksta, SLT-POR procjenjuje vrijednost pouzdanosti zasnovane na kontekstu uporabom kontekstualnih obilježja svakog čvora u nizu pozitivnog pouzdanog djelovanja. SLT-POR u procjeni pouzdanosti pazi da snaga baterije uključuje vijek trajanja čvora, pridaje važnost pouzdanosti zasnovanoj na kontekstu kao i onoj zasnovanoj na ponašanju kako bi učinkovito izračunao ukupnu pouzdanost čvora. Rezultati simulacije pokazuju da je omjer isporuke paketa predloženog SLT-POR visok, čak i ako je 50 % svih čvorova maliciozno te da je bolji od sustava CAST - Context-Aware Security and Trust.In the past decades, several trust models have been proposed to enhance the security of Mobile Ad hoc Networks (MANETs). The conventional trust models fail to express the notion of uncertainty during the establishment of trust relationships between mobile nodes. Furthermore, they lack in considering the context attributes in trust evaluation. This paper proposes a subjective logic based trust model in POR (SLT-POR) that integrates both the behavioural and context based trust in trust model. The behavioural based trust incorporates subjective logic based evidence fusion in indirect trust evaluation to explicitly represent and manage ignorance as uncertainty. The trust relationship between nodes cannot always reflect the actual relationship and consequently the executed decision from the extracted trust relationship is not always accurate. The subjective logic theory includes a dynamic base rate operator that evaluates an expectation of an opinion and handles the uncertainty in evidence collection. In context, attributes based trust measurement, the SLT-POR estimates a context based trust value using the contextual attributes of each node in the trusted positive progress set. The SLT-POR considers the battery power to include node’s lifetime in the trustworthiness estimation. It assigns a weight for both behaviour and context based trust to efficiently calculate total trustworthiness of a node. The simulation results demonstrate that the packet delivery ratio of the proposed SLT-POR is high even if 50 % of total nodes are malicious and outperforms Context-Aware Security and Trust (CAST) framework

GSAR: Greedy Stand-Alone Position-Based Routing protocol to avoid hole problem occurance in Mobile Ad Hoc Networks

The routing process in a Mobile Ad Hoc Network (MANET) poses critical challenges because of its features such as frequent topology changes and resource limitations. Hence, designing a reliable and dynamic routing protocol that satisfies MANET requirements is highly demanded. The Greedy Forwarding Strategy (GFS) has been the most used strategy in position-based routing protocols. The GFS algorithm was designed as a high-performance protocol that adopts hop count in soliciting shortest path. However, the GFS does not consider MANET needs and is therefore insufficient in computing reliable routes. Hence, this study aims to improve the existing GFS by transforming it into a dynamic stand-alone routing protocol that responds swiftly to MANET needs, and provides reliable routes among the communicating nodes. To achieve the aim, two mechanisms were proposed as extensions to the current GFS, namely the Dynamic Beaconing Updates Mechanism (DBUM) and the Dynamic and Reactive Reliability Estimation with Selective Metrics Mechanism (DRESM). The DBUM algorithm is mainly responsible for providing a node with up-to-date status information about its neighbours. The DRESM algorithm is responsible for making forwarding decisions based on multiple routing metrics. Both mechanisms were integrated into the conventional GFS to form Greedy Stand-Alone Routing (GSAR) protocol. Evaluations of GSAR were performed using network simulator Ns2 based upon a defined set of performance metrics, scenarios and topologies. The results demonstrate that GSAR eliminates recovery mode mechanism in GFS and consequently improve overall network performance. Under various mobility conditions, GSAR avoids hole problem by about 87% and 79% over Greedy Perimeter Stateless Routing and Position-based Opportunistic Routing Protocol respectively. Therefore, the GSAR protocol is a reasonable alternative to position-based unicast routing protocol in MANET

Toward reliable data delivery for highly dynamic mobile ad hoc networks

This paper addresses the problem of delivering data packets for highly dynamic mobile ad hoc networks in a reliable and timely manner. Most existing ad hoc routing protocols are susceptible to node mobility, especially for large-scale networks. Driven by this issue, we propose an efficient Position-based Opportunistic Routing (POR) protocol which takes advantage of the stateless property of geographic routing and the broadcast nature of wireless medium. When a data packet is sent out, some of the neighbor nodes that have overheard the transmission will serve as forwarding candidates, and take turn to forward the packet if it is not relayed by the specific best forwarder within a certain period of time. By utilizing such in-the-air backup, communication is maintained without being interrupted. The additional latency incurred by local route recovery is greatly reduced and the duplicate relaying caused by packet reroute is also decreased. In the case of communication hole, a Virtual Destination-based Void Handling (VDVH) scheme is further proposed to work together with POR. Both theoretical analysis and simulation results show that POR achieves excellent performance even under high node mobility with acceptable overhead and the new void handling scheme also works well