Syed Asad Hussain

A reusable software component-based development process model

The concept of component-based development (CBD) is widely used in software (SW) development. CBD facilitates reuse of the existing components with the new ones. The well known architectures of CBD are ActiveX, common object request broker architecture (CORBA), remote method invocation (RMI) and simple object access protocol (SOAP). The objective of this paper is to support practice of CBD by comparing it with traditional software development. This paper also evaluates object oriented (OO) process model and proposes a novel process model for CBD. The importance of repository has also been discussed.

Identification of malicious nodes in an AODV pure ad hoc network through guard nodes

This paper presents a guard node based scheme to identify malicious nodes in Ad hoc On-Demand Distance Vector (AODV) protocol. In this scheme each node calculates trust level of its neighboring nodes for route selection. Trust calculation process involves opinions of other nodes about the node whose trust level is to be determined. If a neighboring node has a trust level lower than a predefined threshold value, it is identified as malicious and it is not considered for route selection. The proposed model does not use any key distribution process and no changes are made in control packets of AODV. Simulation results show that the proposed scheme improves performance of AODV by identifying and removing malicious nodes. Performance of the scheme has been evaluated for three different types of malicious attacks (impersonation attack, colluding nodes attack and black hole attack).

Thermal-Aware Scheduling in Green Data Centers

Data centers can go green by saving electricity in two major areas: computing and cooling. Servers in data centers require a constant supply of cold air from on-site cooling mechanisms for reliability. An increased computational load makes servers dissipate more power as heat and eventually amplifies the cooling load. In thermal-aware scheduling, computations are scheduled with the objective of reducing the data-center-wide thermal gradient, hotspots, and cooling magnitude. Complemented by heat modeling and thermal-aware monitoring and profiling, this scheduling is energy efficient and economical. A survey is presented henceforth of thermal-ware scheduling and associated techniques for green data centers.

An adaptive software development process model

The concept of agile process models has gained great popularity in software (SW) development community in past few years. Agile models promote fast development. This property has certain drawbacks, such as poor documentation and bad quality. Fast development promotes use of agile process models in small-scale projects. This paper modifies and evaluates extreme programming (XP) process model and proposes a novel adaptive process mode based on these modifications.

Optimised priority assignment mechanism for biomedical wireless sensor networks

Biomedical wireless sensor networks (BWSNs) need to guarantee reliable and timely transfer of crucial data in emergency and time critical situations. Current schemes use static/fixed priority assignment mechanism based on source of data and not on the urgency of the data in different situations. This study presents a novel data transmission scheme, called optimised priority assignment mechanism (OPAM) for BWSNs. The proposed work dynamically schedule different types of data flows based on their time critical nature. It smartly assigns priority to individual data packets rather to particular service or flow by continuously monitoring queuing delay providing guaranteed end-to-end quality of service (QoS) without invoking any congestion control and avoidance mechanism. Experimental results show that OPAM performs better in terms of average throughput and end-to-end delay 55 and 20.5%, respectively, than routing service framework for standard BWSNs.

Persistent packet reordering attack in TCP based Ad hoc wireless networks

This paper investigates congestion behavior of TCP and its variants TCP Reno, TCP NewReno, TCP Sack1, TCP Vegas, TCP Rbp and TCP Fack for AODV (Ad hoc Ondemand Distance Vector) and DSR (Dynamic Source Routing) routing protocols under persistent packet reordering attack through simulations in NS-2. It also proposes a solution to counter misinterpretation packet reordering with packet loss when retransmissions are due to persistent packet reordering by malicious nodes rather than packet loss due to traditional reasons.

A Trust based Security Framework for Pure AODV Network

This paper presents a trust based security framework to identify malicious nodes in ad hoc on-demand distance vector (AODV) protocol. In this framework each node calculates trust level of its neighboring nodes for route selection. Trust calculation process involves opinions of other nodes about the node whose trust level is to be determined. If a neighboring node has a trust level lower than a predefined threshold value, it is identified as malicious and it is not considered for route selection. The proposed security framework does not use any key distribution process and no changes are made in control packets of AODV. Simulation results show that the proposed framework improves performance of AODV by identifying and removing malicious nodes. Performance of the framework has been evaluated for three different types of malicious attacks (impersonation attack, colluding nodes attack and black hole attack).

Thermal-aware relocation of servers in green data centers

Rise in inlet air temperature increases the corresponding outlet air temperature from the server. As an added effect of rise in inlet air temperature, some active servers may start exhaling intensely hot air to form a hotspot. Increase in hot air temperature and occasional hotspots are an added burden on the cooling mechanism and result in energy wastage in data centers. The increase in inlet air temperature may also result in failure of server hardware. Identifying and comparing the thermal sensitivity to inlet air temperature for various servers helps in the thermal-aware arrangement and location switching of servers to minimize the cooling energy wastage. The peak outlet temperature among the relocated servers can be lowered and even be homogenized to reduce the cooling load and chances of hotspots. Based upon mutual comparison of inlet temperature sensitivity of heterogeneous servers, this paper presents a proactive approach for thermal-aware relocation of data center servers. The experimental results show that each relocation operation has a cooling energy saving of as much as 2.1 kW·h and lowers the chances of hotspots by over 77%. Thus, the thermal-aware relocation of servers helps in the establishment of green data centers.

Beaconless multihop routing protocol for wireless sensor networks

Routing is a major challenge in sensor networks, due to constrained resources of energy, processing power, and memory. This proves that there is an urgent need to design energy efficient routing protocols for sensor networks for prolonging network lifetime. This paper presents a new beaconless multihop routing algorithm (BMR) for wireless sensor networks which is light weight, energy efficient and makes routing decisions based on residual energy of nodes. Additionally BMR is a non-positioned beaconless routing protocol which eliminates the overhead of control messages exchanged during network setup in cluster based routing protocols. The proposed protocol first divides the whole network into different zones using message passing techniques by Base Station (BS) and performs energy efficient location base routing without taking any assumption of location services. A simulation-based evaluation is conducted to compare the performance of BMR against energy efficient protocol with static clustering for wireless sensor networks (EEPSC). Simulation results show that BMR performs better than EEPSC in terms of network lifetime and energy consumption minimization.

A game theory based trust model for Vehicular Ad hoc Networks (VANETs)

Vehicular Ad hoc Networks (VANETs) facilitate road safety, transportation security, reliability and management. This paper presents a game theory based trust model for VANETs. The proposed model is based on an attacker and defender security game to identify and counter the attacker/malicious nodes. The parameters considered for attackers and defenders strategy are majority opinion, betweenness centrality, and node density. The outcome of the specific game is determined by the game matrix which contains the cost (payoff) values for possible action-reaction combination. Nash equilibrium when applied to calculate the best strategy for attacker and defender vehicles. The model is simulated in Network Simulator (ns2), and results show that the proposed model performs better than the schemes with random malicious nodes and existing game theory based approach in terms of throughput, retransmission attempts and data drop rate for different attacker and defender scenarios.