Recent Trends in Wireless and Mobile Networks

Designing mobility and power aware routing protocols have made the main focus of the early contributions to the field of Mobile Ad-hoc NETworks (MANETs). However, almost all conventional routing protocols for MANETs suffer from their lack of adaptivity leading to their performance degradation under varying network conditions. In fact, this is due to both simplistic conception hypotheses they made about the network and to the use of some prefixed parameters in protocols implementations. Currently, artificial intelligence methods like Reinforcement Learning (RL) are widely used to design adaptive routing strategies for MANETs. In this paper, we present a comprehensive survey of RL-based routing protocols for MANETs. Besides, we propose some future research directions in this area.

Mobile Adhoc Network (MANET) is highly vulnerable to malicious attacks due to infrastructure less network environment, be deficient in centralized authorization. The fact that security is a critical problem when implementing mobile ad hoc networks (MANETs) is widely acknowledged. One of the different kinds of misbehavior a node may exhibit is selfishness. Routing protocol plays a crucial role for effective communication between mobile nodes and operates on the basic assumption that nodes are fully cooperative. Because of open structure and limited battery-based energy some nodes (i.e. selfish or malicious) may not cooperate correctly. There can be two types of selfish attacks –selfish node attack (saving own resources) and sleep deprivation (exhaust others’ resources. In this paper, we propose a new Mobile Agent Based Intrusion Detection System (IDS). The approach uses a set of Mobile Agent (MA) that can move from one node to another node within a network. This as a whole reduces network bandwidth consumption by moving the computation for data analysis to the location of the intrusion. Besides, it has been established that the proposed method also decreases the computation overhead in each node in the network.

Wireless sensor networks consist of hundreds or thousands of small sensors with have limited resources. The energy resource is the most challenging one to be maintained. The major reason for power drain is the communication between sensor nodes. Most of the routing algorithms for sensor networks focus on finding energy efficient paths to prolong the lifetime of the networks. In this paper, a novel routing algorithm has been proposed to detect the source of an event in the network. This algorithm also maintains a balance between the powers of different nodes in the network, so that the longevity of the overall network may increase.

A distributed and adaptive clustering algorithm is proposed in this paper. A distributed algorithm is based on dominating set. Dominating set is used for selection of cluster head and gateway nodes. The quality of cluster head is calculated based on connectivity, stability and residual battery power. Clustering is a method to build and maintain hierarchical addresses in mobile adhoc networks. Here, several clustering algorithms are surveyed concentrating on those that are based on graph domination. Long term service as cluster head depletes their energy, causing them to drop out of the network. Stable, secure cluster head selection increases lifespan and security of the network. This technique maintains cluster structure as stable as possible.

The next-generation mobile and wireless communications will be supported by an all-IP based infrastructure which requires an effective mobility management protocol to support ubiquitous network access by providing seamless handover. However, the recent explosion on the usage of mobile devices has also generated several issues in terms of performance and quality of service (QoS). Nowadays, mobile users demand high quality performance, best QoS and seamless connections that support real-time application such as audio and video streaming. This paper aims to study the impact and evaluate the mobility management protocols under micro mobility domain on link-layer and network-layer handover performance. We propose an integrated solution of network-based mobility management framework, based on Proxy Mobile IPv6, to reduce handover latency when mobile host moves to new network during handover on high speed mobility. We conducted simulations and analyze the network performances for mobile host under high speed for the proposed mobility protocols.

The most appropriate modulation and channel coding for a Very Small Aperture Terminal (VSAT) system is Quadrature Phase Shift Keying (QPSK). The Channel can be wire or wireless voice and data applications due to its flexible system architecture. In this paper, a Simulink based QPSK system is simulated to study the characteristic performance analysis of Additive White Gaussian Noise (AWGN) channel. Simulation study helps to visualize eye-diagram and Root Raised cosine (RRC) Filter with scatter plot. The error rate is calculated by comparing a transmitted data stream with a receive data stream with the help of delay introduction. Characteristic performance analysis is done by comparing the un-coded data with coded data using two different models. The Bit Error Rate (BER) curve for a Communication system illustrates the relationship between power in the transmitted signal in terms of signal to noise ratio (SNR) and the resulting BER for the system.

Vehicular Ad Hoc Networks (VANETs) are considered as a promising approach for facilitating road safety, traffic management, and infotainment dissemination for drivers and passengers. However, they are subject to an attack that has a severe impact on their security. This attack is called the Sybil attack, and it is considered as one of the most serious attacks to VANETs, and a threat to lives of drivers and passengers. In this paper, we propose a detection scheme for the Sybil attack. The idea is based on public key cryptography and aims to ensure privacy preservation, confidentiality, and non-repudiation. In addition, we suggest a scalable security and privacy solution using short-lived and authenticated certificates that must be issued from the national certification authority in order to guarantee trust among vehicles.

Different protocols have been developed throughout the last years to achieve automatic IP address allocation in Mobile Ad hoc Networks (MANETs). However, Autoconfiguration security issues are still an open problem. In this paper, a new secure and robust IP Address allocation protocol for standalone MANETs inspired from MANETconf and named TCSAP is specified and evaluated within NS2. The proposed solution is efficient and thwarts all possible attacks associated with dynamic IP address assignment in MANETs.

Wireless Sensor Networks (WSN) consist of low powered and resource constrained sensor nodes which are left unattended for long duration of time. Hence it is very challenging to design and implement cost effective security protocols for such networks. Thus symmetric key cryptographic techniques are preferred over public key techniques for communication in such scenarios. Prior to deployment, keys are usually predistributed into the nodes and this problem has been well studied. Highlighting that connectivity and communication are two separate aspects of a WSN, we propose a secure connectivity model using Reed Muller codes. The model is then utilized to securely establish communication keys and exchange messages in a WSN designed on the basis of a scheme that uses affine planes for key predistribution. Novel combination of both the ideas yields highly resilient communication model with full connectivity between nodes.

To speed up the processing of continuous range queries over moving objects data streams, various query indexing techniques have been proposed. We present a cyclic-translation-based Grid-Quadtree query index and use the methods of query location translation and index tuning to optimize the indexing of continuous range queries. We study the performance of our indexing approach and compare it with a prior CES-based indexing approach.

k

-means has recently been recognized as one of the best algorithms for clustering unsupervised data. Since the

k

-means depends mainly on distance calculation between all data points and the centers then the cost will be high when the size of the dataset is big (for example more than 500MG points). We suggested a two stage algorithm to reduce the cost of calculation for huge datasets. The first stage is fast calculation depending on small portion of the data to produce the best location of the centers. The second stage is the slow calculation in which the initial centers are taken from the first stage. The fast and slow stages are representing the movement of the centers. In the slow stage the whole dataset can be used to get the exact location of the centers. The cost of the calculation of the fast stage is very low due to the small size of the data chosen. The cost of the calculation of the slow stage is also small due to the low number of iterations.

A mobile ad-hoc network (MANET) is an autonomous system of mobile nodes which are free to move randomly thus forming a temporary network. Typical applications of MANET are in disaster recovery operations which have to respect time constraint needs. However, it is very difficult to guarantee any quality of service to a real-time flow in such network because it must take into account the specificities of these networks. This paper introduces the Energy Delay aware based on Dynamic Source Routing, ED-DSR. ED-DSR efficiently utilizes the network resources such as the node energy and the node load in order to balance traffic load. It ensures both timeliness and energy efficiency by avoiding low-power node and busy node. Simulation results, using NS-2 simulator, show that the protocol prolongs the network lifetime (up to 66%), increases the volume of packets delivered while meeting the data flows real-time constraints and shortens the end-to-end delay.

In this paper, we proposed a technique to extend the network lifetime of a wireless sensor network, whereby each sensor node decides whether to transmit a packet or not and with what range to transmit the packet. A sensor node makes this decisions based on its own energy resource and the information contained in each packet. The information content in each packet is determined through a system of rules describing prospective events in the sensed environment, and how important such events are. While the most important packets are propagated by virtually all sensor nodes and with different transmission ranges depending on their battery life, low importance packets are propagated by only sensor nodes that have high energy reserves and with greater transmission ranges due to high reserves. The result show that by adjusting the transmission ranges based on energy reserves, a considerable increase of lifetime is achieved.

We will present a new Hybrid Routing Algorithm with Special Parameters in Wireless Sensor Network for network with many sensors. This algorithm will select the cluster heads (CH) based on the scale of average local energy and the density surrounding each node. In the presented algorithm a type of mechanism was used in which it performs cluster formation in special conditions with regard of the neighborhood principle and local information of a node and its neighbors. Also in PRWSN the data of each cluster is sent to BS via a hybrid method. In networks with high density which use multi-hop methods, the energy of nodes close to BS will be discharged with a higher speed while in single-hop methods the energy of nodes which are far from BS will be diminished earlier. To overcome these problems, we use a combination of the single and multi-hop methods for increasing the lifetime of the network. In the presented algorithm, parameters such as the distance to the Base Station and energy are used to choose the next step in the hybrid method. Finally, with the results of multiple simulations we were able to show that PRWSN, in comparison with the previous Clustering Algorithm has increased the lifetime of sensor network, and reduced the amount of node energy consumption by balancing the use of energy between nodes, therefore resulting to a more suitable distribution of clusters in the sensor network. Hence, this algorithm is more effective compared to the previous algorithms.

Wireless terrestrial networks are usually designed in 2D plane, but in real life they form 3D space. In these networks, node placement strategy is one of the most important design problems. The idea is to deploy a number of nodes in an effective way to achieve communication between them. The volumetric quotient, which is the ratio of the transmission range to the sensing range of each node, is used as the main measure of the placement strategy. Researchers use polyhedrons to model 3D networks. As the volumetric quotient increases, we need less number of nodes for full coverage. In this paper, we proposed a cone model which gives a higher volumetric quotient than polyhedrons. The inspiration comes from satellite foot-print. For example, the number of nodes for truncated octahedron placement strategy is found to be 46.35% higher than the cone placement strategy. We also achieved full coverage with cone tessellation.

Delay-tolerant Networking (DTN) is an attempt to extend the reach of traditional networking methods where nodes are intermittently connected and an end-to-end path from source to destination does not exist all the time. Real networks like military, various sensors, post disaster management, deep space communication, Vehicular ad-hoc (VANETs) networks, are some examples of DTN. Our work mainly concentrates on the applicability of different flooding based routing scheme of DTN in

post disaster scenarios

. Cluster mobility model which maps human mobility more realistically rather than any other mobility in the context of disaster scenario has been considered. Further we have customized cluster mobility model according to the disaster like scenario and performed the simulation for delivery probability with respect to various constraints like buffer-size, transmission range, speed and density of nodes in ONE SIMULATOR. We also analyze the effect heterogeneous nodes in delivery probability.

The performance in term of Bit Error Rate (BER) of smart antenna receivers calls for some simplification of the interference reduction capability. Obviously, the receiver performances are strictly related on the efficiency of MAI reduction. In order to gain from the enhancements of both: multiuser detection and adaptive antenna , we propose in this paper a hybrid scheme of diversity and smart antennas called Hierarchical Beamforming (HBF), to jointly combat fading and MAI. Our analysis is based on modeling the HBF receiver and the description of the simulation strategy employed to simulate its performance. Moreover, we compare the performance of HBF receiver with Conventional Beamforming (CBF) one. The proposed model conforms the benefits of adaptive antennas in reducing the overall interference level (intercell/intracell) and to find an accurate approximation of the error probability.

Delay Tolerant Networks (DTNs) are a class of networks that make communication in stressed and challenging environments possible. DTN is characterized with a number of unique features by virtue of which a working environment is achieved in situations where traditional networking paradigms fail to deliver satisfactorily or entirely. The utility of multicasting in DTNs extends to numerous potential DTN applications i.e., crisis environments, battlefield situations, deep space communications, dynamic data size management, etc. In this paper, we propose taxonomy for the different multicast routing strategies and thereafter, we present a comprehensive up to date survey of these strategies. Further, we perform a qualitative comparison between the different multicast strategies with respect to important performance issues in DTN. We also highlight some unexplored areas in DTN multicasting that could inspire research in the near future.

Radio Frequency Identification (RFID) which is a mature identification and tracking technology recently is picking up its momentum with the emergency of a highly hyped "Internet of Things" (IOT). The ultimate goal of IOT is to let human and objects seamlessly talk to each other via the Internet. It finds great impacts on our lifestyles in various applications such as supply chain management, access control security, mobile health-care, etc. In response to this technology trend and market demands, a high level infrastructure called EPC (Electronic Product Code) network with Object Naming Service has been proposed that rides on the future IPv6 Internet. In order to enable the operation of EPC network, auxiliary mechanisms such as privacy and security protection, context-aware capabilities, middleware and interoperable data semantics are needed. In this paper we propose a prototype of wireless communication system incorporated with Internet capability, namely Internet RFID. In particular, this paper shows the preliminary design, implementation and testing of the Internet RFID prototype in a client-server environment. As an experiment, we implemented a typical RFID system with the additional feature of distance finding that can track and monitor access control, and at the same time a database located remotely in a Web Server is updated. Users can query the Web database server in real-time about the location of the client. The hardware module consists mainly of the construction of two micro-controller systems: one for the user card and the other one for the station transceiver controller. Recommendations are provided at the end of the paper for future development.

Particle Swarm Optimization (PSO) is an evolutionary metaheuristic. It was created in 1995 by Kennedy and Eberhart for solving optimization problems. However, several alternatives to the original PSO algorithm have been proposed in the literature to improve its performance for solving continuous or discrete problems. We propose in this paper 4 classes of binary PSO algorithms (BPSO) for solving the NP-hard knapsack problem. In the proposed algorithms, the velocities and positions of particles are updated according to different equations. To verify the performance of the proposed algorithms, we made a comparison between algorithms of the 4 proposed classes and a comparison between the proposed algorithms with the Standard PSO2006 and the Standard BPSO. The comparison results showed that the proposed algorithms outperform the Standard PSO2006 and the Standard BPSO in terms of quality of solution found.

CRC (Cyclic Redundancy Check) is used as an error detection code in Ethernet frames. This method attaches the residue of a modulo-2 division to the message in the sender side and recalculates the residue in the receiver side. The agreed-upon divisor is called the generator. The range of detectable errors in this method is determined by the properties of the generator. In this paper a systematic approach is proposed to identify all proper generators which can be used in Ethernet networks in order to detect double bit errors which invert a pair of bits in the message.

In this paper, we analyze the security vulnerabilities of SSL-MAP, an ultra-lightweight RFID mutual authentication protocol recently proposed by Rama N, Suganya R. We present two effective attacks, a de-synchronization attack and a full-disclosure attack, against this protocol. The former permanently disables the authentication capability of a RFID tag by destroying synchronization between the tag and the RFID reader. The latter completely threats a tag by extracting all the secret information that are stored in the tag. The de-synchronization attack can be carried out in three round of interaction in SSL-MAP while the full-disclosure attack is accomplished across several runs of SSL-MAP. We also discuss ways to counter the attacks.

In this paper we propose an algorithm for distributing files among moving vehicles through multiple Road Side Units (RSUs). It is assumed that the RSUs are connected and are under the management of a central administration. Thus all RSUs have all the files. Our approach includes two scheduling algorithms: intra-RSU and inter-RSU. The former handles broadcast scheduling of files inside each RSUs coverage area and the latter handles resumable broadcasts from other RSUs. Therefore, it is possible to resume downloading file(s) from other RSUs when the file(s) can not be downloaded completely from a RSU. Furthermore, all files are encoded by means of Fountain Coding techniques meaning that all packets have the same value and there is no need of receiving packets in-order. Consequently, we are able to distribute files with a low overhead and without need of reliable and ACK-based transport protocols such as TCP. Using extensive simulation study we have evaluated the effect of using fountain coding, vehicles’ speed, file size and number of RSUs on the performance of the proposed algorithm.

With the progressive expansion of computer networks and their increasing complexity, it becomes considerably difficult for administrators to ensure the maintenance of these networks with reasonable efforts and in acceptable times.

In this paper, we investigate the potential use of mobile agents in networks management problem. To this end, we propose the use of a multi-agent system (MAS) to solve problems related to improper configuration of IP addressing. This will provide a desirable autonomy in terms of self management to the network reducing considerably human intervention.

For the implementation of our MAS we use the JADE platform which provides classes in the form of a set of behaviors ready to use. The simulation of the prototype is done in an Ethernet environment context, where the bus is configured with four nodes concentrated on a single switch. We show through numerous screenshots the feasibility of such a solution.

With the arrivals of 3G/4G mobile networks, a diverse and new range of applications will proliferate, including video-on-demand, mobile-commerce and ubiquitous computing. It is expected a sizable proportion of these traffics move along the networks. Resources in the networks will have to be divided between voice support and data support. For the data support, multiple classes of services from the new mobile applications that have different requirements have to be monitored and managed efficiently. Traditionally Quality-of-Service (QoS) resource management was done by manual estimation of resources to be allocated in traffic profiles in GSM/GPRS environment. The resource allocations parameters are adjusted only after some period of time. In this paper, we propose a QoS resource allocation model that dynamically monitors every aspect of the network environment according to a hierarchy of QoS requirements. The model can derive knowledge of the network operation, and may even pinpoint the cause, should any anomaly occurs or malfunctions in the network. This is enabled by a hierarchy of classifiers or decision-trees, built stream-mining technology. The knowledge from the classifiers is inferred by using reasoning-of-evidence theory, and it is used for subsequent resource allocation. By this way, the resources in the network will be more dynamically and accurately adjusted, and responsive to the fluctuating traffic demands.

Cryptographic algorithms are the most essential elements in designing the system security. Though there are numerous encryption systems used in security systems by various organizations, for the wider use, a particular encryption method is used as a standard. The internationally accepted and acclaimed algorithm is Advanced Encryption Standard. Here in this paper we have implemented the Advanced Encryption Standard (AES) using hardware descriptive language (HDL) and constructed a modified S-box. Area and power of both S boxes are compared and their resistance to attack is also analyzed.

This paper provides a survey of middleware system for Internet of Things (IoT). IoT is considered as a part of future internet and ubiquitous computing, and it creates a true ubiquitous or smart environment. The middleware for IoT acts as a bond joining the heterogeneous domains of applications communicating over heterogeneous interfaces. Comprehensive review of the existing middleware systems for IoT is provided here to achieve the better understanding of the current gaps and future directions in this field. Fundamental functional blocks are proposed for this middleware system, and based on that a feature wise classification is performed on the existing IoT-middleware. Open issues are analyzed and our vision on the research scope in this area is presented.

In a multi-organization environment like the GRID, each institute might want to implement limits on how its resources are being used by other institutes. The problem in most traditional policy frameworks lies in the fact that it concentrates on the policy management inside the VO rather than on the management between multiple VOs. The external users, who want to utilize resources in the GRID, ask for guarantees for their jobs and data which most recent policy frameworks do not take into consideration. To date, not enough attention has been paid to policies that deal with such concerns since most existing Grid systems have supported only limited types of policies. This paper introduces a new dynamic framework that supports the management of security policies within the VOs along with the support for the data policies with addressing external users’ policies when making decisions.

Due to small cell size deployment of IEEE 802.11 WLAN is limited to buildings and small campuses. User moving out of the coverage area of AP gets disconnected from WLAN. IEEE 802.16 is a WMAN technology which is gaining popularity because of its good bandwidth and wide coverage area. For seamless mobility, the coverage area of WLANs may be made to fall within the coverage area of a WMAN. User devices having both WLAN and WMAN interfaces can perform vertical handoff to WMAN while moving out of range of WLAN network. Devices needs to perform network entry process while joining a WMAN and requires considerable time to handoff from WLAN to WMAN. For real time applications like VoIP, handoff latency needs to be within 50 ms. In this paper we propose a scheme where vertical handoff latency is reduced to zero.

The load distribution in a grid may vary leading to the bottlenecks and overloaded sites. We describe a hierarchical dynamic load balancing protocol for Grids. The Grid consists of clusters and each cluster is represented by a coordinator. Each coordinator first attempts to balance the load in its cluster and if this fails, communicates with the other coordinators to perform transfer or reception of load. This process is repeated periodically. We analyze the correctness, performance and scalability of the proposed protocol and show from the simulation results that our algorithm balances the load by decreasing the number of high loaded nodes in a grid environment.

This work presents a P2P based grid scheduling system for highly dynamic and highly heterogeneous environments, such as home networks, where we can find a variety of devices (laptops, PCs, game consoles, etc.) and networks. Our solution is based on the distribution of the matchmaking task among providers, leaving the final allocation decision to a central scheduler that can be running on a limited device without a big loss in performance. We evaluate our solution by simulating different scenarios and configurations against the Opportunistic Load Balance (OLB) scheduling heuristic, which we found to be the best option for home grids from the existing solutions that we analyzed. The results have shown that our solution performs similar to or better than OLB.

The field of resource sharing has become an increasingly important computing field of study for both industry and academia. Facilitating the use of geographically distributed resources is a complex task encompassing many sub tasks. The most important sub-tasks are advertising the available resources across the network and the discovery of these resources. In this paper, the task of advertising the resources has been studied from a network point of view. An advertisement model has been designed using multi-agent system techniques to achieve decentralization and to cope with the dynamic nature and behaviour of the system. The design has been implemented and tested under a simulation environment using the network simulator ns-2. The system evaluation has shown promising results in terms of the system performance itself and the effect of the advertising overhead on a working network’s performance.

One of the biggest challenges for nowadays biologist is the identification, characterization and gene-gene interactions detection for common human diseases such as cancer and diabetes. This challenge is partly due to the explosion of biological information. The multifactor dimensionality reduction (MDR) method can be used to address this problem. This method can be computationally intensive, especially when more than ten polymorphisms need to be evaluated. The Grid is a promising architecture for genomics problems providing high computing capabilities. In this paper, we describe a framework for supporting the MDR method on Grid environments. This framework helps biologists to automate the execution of multiple tests of gene-gene interactions detection.

Nowadays mobile devices are very popular and users expect to run the same applications on mobile devices as onstatic computers. However, these devices oftenhave lower performance than static computers that is due to the constraints imposed on mobile devicesby weight, size, and mobility. Cyber foraging approaches have tried to amelioratethe lower performance of mobile devices by exploiting more powerful static computersto run some computational intensive taskson behalfof mobile devices. Unfortunately, these approaches havenot been effective in all contexts. In this paper, we propose a new context-aware cyber foraging approachto select the best location to run an application, based oncontext metrics such as application specification, computation cost and communication cost. Experimental results show the superiority of ourproposed approach in achieving lower response time andenergy consumptionin executing some benched applications compared to when these applications are solely run on mobile devices or when theseapplications aretotallyoffloaded blindly to surrogates for execution.

A domain model may be designed in iterations, where each iteration is validated through a default application generated from the model. By adding, editing, removing, retrieving and navigating real data it becomes obvious what is wrong with the model. Once the model is validated, user views of the model may be developed by reusing generic components or by developing specific components. Modelibra is a software family of tools and frameworks that supports this prototyping process of designing domain models and their views.

$\mathcal{A}^{xml(T)}$

is a logic-based formal language of authorisation for documents written in the Extensible Markup Language. In our previous publication, we addressed the issues of the syntax, semantics, and expressive power that it has to specify access control and to query XML encoded data. In this paper, we consider an experimental implementation to test its capability to allow and restrict access to XML documents. The software implementation will allow us to define a security policy base and then reason upon it to determine authorisations. From there we can discover

$\mathcal{A}^{xml(T)}$

’s capacity to provide XML access control and any limitations it may have. Also, from this experiment we will have an initial building block for establishing an actual XML access control application.

Could computing is the latest development of the modern computing technology. It is the next stage of the Internet evolution. Cloud computing provides the organizations with the infrastructure management, various software services and the datacenter maintenance. The organizations can reduce their operational cost and concentrate on their strategic planning by using services provided by cloud computing. Generally, the success of cloud computing depends on three key issues: data security, fast Internet access and standardization [17]. Among the three issues, the biggest concern is data security. In this paper, we investigate the security issue related to datacenter of cloud computing. By analyzing the properties of the data stored at the datacenter, we propose a logical approach to specify the data and employ intelligent agents to enforce appropriate security policies on it. We expect such approach will protect the datacenter by only allowing the legitimate users accessing the data and preventing any malicious attempt to it.

One major Disadvantage of OFDM is the high peak-to average Power ratio (PAPR). One investigated technique Selected Mapping (SLM) is PAPR reduction techniques for Orthogonal Frequency Division Multiplexing (OFDM). In this paper we proposed a Modernize SLM (MSLM) scheme to reduce the PAPR by using the complex signal separate into real & imaginary parts and individually phase sequence multiple real as well as imaginary part of complex signal then select minimum PAPR signal of real & imaginary and these are combine. The simulation show achieves good PAPR., which is one of the strong candidate for Future wireless communication.

Tendering is an important issue that requires Decision Support System (DSS) attention as a decision to award tenders to certain competing applications could influence successful completion of a project. This paper presents a framework of DSS for a tendering process based on a combination of single criteria statistical model, weighted model and an extended AHP model known as Guided AHP (GAHP). This hybrid model allows single criteria tender prices which are considered abnormal to be excluded from further detail multicriteria GAHP evaluation. GAHP is proposed to minimize the possibility of inconsistent data entry and to improve evaluation accuracy and flexibility. The use of model integration takes the advantage of their strengths and complements each other’s weaknesses. Finally, a real organizational government tendering application is applied to demonstrate the potential of the proposed framework.

The extensible Markup Language (XML) has evolved into a widespread standard for representation of voluminous data and data exchange among heterogeneous sources. The two major constraints in XML applications are its size and querying efficiently. In this paper, we have proposed an efficient storage structure called QUICX that supports both query and update efficiently. The storage space for the XML document is reduced substantially by completely eliminating redundant tags and data’s. The size of data is further reduced by applying efficient compression techniques on the data’s. Indexing is performed to the compressed data to increase the efficiency of querying; QUICX has significant improvements on compression ratio among its Peer systems. In effect QUICX provides a full fledged system to store and manipulate XML document efficiently. Performance has been evaluated using the Benchmark datasets using the existing techniques as well as with this proposed technique. From these evaluations, it is seen that the proposed compact storage structure and algorithm have significant improvements than the existing tested systems.