L. A. Latiff

GPS-free indoor location tracking in mobile ad hoc network (MANET) using RSSI

More devices in the future will be connected to the Internet wirelessly and also these devices can move within the coverage area of the mobile network. A mobile ad hoc network consists of devices or nodes that are able to communicate among themselves. These nodes also serve as routers and can dynamically move around arbitrarily at any speed in any direction resulting in an ever-changing topology for the MANET. Due to the node mobility, the most challenging issue is to design a routing protocol that guarantees delivery of packets. In order to improve the network routing performance, a limited casting technique is adopted which requires the ability to establish position information. Once each nodes location is determined, the distance between nodes can be derived and the number of hops to the destination can be computed. A GPS-free indoor position tracking system has been developed that provides knowledge of the geometric location of nodes in a MANET.

Development of an indoor GPS-free self-positioning system for mobile ad hoc network (MANET)

Position location (PL) has been an important and motivating criterion in position-based routing protocols which will reduce routing overhead. Several PL technologies such as Global Positioning System (GPS), the active badge system, the bat system and the cricket compass system have been proposed. GPS technology is very useful outdoor but quite ineffective indoors because walls in buildings block GPS transmissions. Other systems mentioned above are hardware-based which require additional devices for signal transmission and this will significantly incur additional cost of installation and maintenance. In this paper, the development of a GPS-free, simple self-positioning system to be implemented in MANET are presented where the node itself determines its location from hello message signals received that are being broadcast at intervals from specifically identified stationary nodes. Location of all nodes will be based on a global coordinate system which will provide a simpler routing task in any position-based routing protocol. The proposed system will be economically developed since the hardware required are laptops or PDAs with a standard IEEE 802.11 wireless LAN card which will have a relative large transmission coverage compared to Bluetooth and infrared signals.

Real-Time Routing in Wireless Sensor Networks

In wireless sensor networks (WSNs), sensors gather information about the physical world and base station makes appropriate decision upon the environment. This technology enables users to effectively sense and monitor from a distance. WSN are slated to become very popular in the near future. It allows video/audio streaming to be transferred between sensor nodes in real-time. WSN can use real-time forwarding which means messages in the network are delivered according to their end-to-end deadlines (packet lifetime). This paper proposes a novel real-time routing protocol based on link quality, packet velocity over one-hop and remaining power in the sensor devices. The proposed routing has been successfully studied and verified through simulation and real test bed implementation. The results in this paper show that the proposed routing protocol has efficient power consumption, high packet delivery ratio and minimum control packet overhead in WSNs.

Power reduction quadrant-based directional routing protocol (Q-DIR) in Mobile Ad Hoc Network

Flooding of request packet in the route discovery phase in Mobile Ad Hoc Network (MANET) creates a broadcast storm which increases the probability of packet collisions. With location information of the destination node, the source node and also of the current node, route request will be more directed towards destination since nodes that are within the directed region will participate in the routing process. Hence, nodes that are out of the trajectory will ignore the packet and thus reduces the number of broadcasting nodes and consequently, less probability of collisions. This paper presents Quadrant- based directional routing protocol (Q-DIR) algorithm that limits the broadcast region to a quadrant where the destination node and source node are located. Q-DIR utilizes location information of the destination node, the source node and the current node. With Q-DIR as a reactive routing protocol, routing overhead will be reduced and consequently, reduces total network power consumption through limited flooding. This paper will present the performance of Q-DIR in a densely populated network of 49 nodes.

Accuracy Enhancement of Fingerprint Indoor Positioning System

There are several researches have been conducted and different methods have been applied to extend the features of indoor location tracking using wireless devices. Fingerprint algorithm is one of the popular methods that have been used to track mobile nodes in indoor structure. This paper focuses on the enrichment of positioning accuracy of the Fingerprint algorithm. RSSI mechanism has been used on the Fingerprint Algorithm to encompass better performance for the accurate positioning. The paper has been proposed two different types of Fingerprint methods and their performance variants on different circumstances of indoor environment. The proposed Fingerprint Database mapping has been divided according to the RSSI data redundancy. The proposed Fingerprint methods has been successfully implemented and experimented on UTMMIMOS CoE lab. The experimented results of two Fingerprint methods has been analyzed and compared as well.

An Indoor 3D Location Tracking System Using RSSI

Representation of indoor 3D location tracking had been an advantage to globally supported to track the mobile unit everywhere, even in different level of building. Our main focus is presenting development of indoor 3D location tracking to replace the existing 2D location tracking. The 2D location tracking mechanism only supports tracking the mobile unit position in the same level and provides handover or device switching. If the users need to go to another level, user will have to disconnect the connection. The development of the system that has a location tracking mechanism responsible to track the position of the mobile unit (such as laptop and PDA). In this paper, the system running in IPv4 framework and set up as a read test bed. The proposed location tracking will be based on Received Signal Strength Indicator (RSSI). The 3D location tracking system will be purely software based with minimum hardware dependent.

Implementation of enhanced lightweight Medium Access (eL-MAC) protocol for wireless sensor network

Wireless sensor network (WSN) is increasingly being used in a variety of applications which include habitat monitoring, smart health care system, building automation, to name a few. Many approaches were developed for all protocol layers, but an energy-efficient Medium Access Control (MAC) layer remains a key design challenge. MAC with scheduled based architecture provides greater advantage over other designs, such as contention-based and frequency division multiple access (FDMA), in terms of minimizing packet collision, overhearing, idle listening, and over emitting. Reliable and energy efficient data transmission are required to prolong the network lifetime. This paper presents the testbed development of an enhanced lightweight medium access (eL-MAC) protocol which introduces distributed time slot assignment and slotting communication mechanism. Therefore, with eL-MAC, idle listening, overhearing and hidden terminal will be eliminated where nodes transmit in its own time slot and sleep in other time slot if there is no activity. This will reduce energy consumption as nodes are active when transmitting and receiving and idle only in the beacon session. The testbed is developed using TelosB sensor nodes programmed with TinyOS. NesC programming language was used to implement the protocols in the WSN module. Experimental results were compared to the results obtained from simulation. As expected, there is a slight degradation in throughput and packet received ratio in the experiment but is consistent for all values. This concludes that the developed testbed reflects the eL-MAC protocol and has been successfully implemented.

Joint resource allocation and sensing scheduling for cognitive ultra wideband

Cross layer design is considered as an attractive strategy to enable multimedia transmission over cognitive ultra wide band (C-UWB) system experiencing time-varying channel conditions and traffic characteristics. The close dependency among various parameters across protocol stacks need to be addressed to determine the optimum cross layer approach. Hence, this paper highlights a MAC centric cross layer approach that is aware of sensing activity and channel conditions at the PHY layer, resource allocation at the MAC layer and MPEG-4 video at the APP layer. The cross layer actions are determined through optimal sensing scheduling and dynamic packet reception rate (PRR) based resource allocation to improve video transmission quality. Two important sensing approaches, local and cooperative OR-rule are also discussed in detail. Then, the impact of the proposed sensing scheduling and resource allocation to the video transmission are evaluated accordingly.

Indoor location-assisted device switching system for VoIP application

Ubiquitous computing for context aware system collects information from many static and moving devices as well as sensor integrated objects. To provide valuable services, it is necessary to track the location of the users or objects. There are many possible applications that can apply location-assisted service such as child tracking, supermarket trolley alert system, firefighter tracking and many more. This paper proposed an indoor location assisted device switching for Voice over Internet Protocol (VoIP) application using session initiated protocol (SIP) for Wireless Local Area Network (WLAN) based. We present real test-bed measurements for indoor environment giving the results of the system operation as well as the system performance. The system performance shows excellent accuracy of 1m.

Geodirectional-cast forwarding based on quadrant for real-time routing in Wireless Sensor Network

Directional forwarding is forwarding to the next nodes that have the optimal progress towards destination while geocast forwarding is forwarding of packets to nodes within a certain geographic area. This paper proposes new type of communication in wireless sensor network (WSN) called geodirectional-cast forwarding based on quadrant. Geodirectional-cast forwarding combines geocast with directional forwarding to forward the data packet through multiple paths within a certain geographic area to destination. Forwarding based on quadrant means neighboring nodes that are in the same quadrant will only participate in this routing phase. This paper presents the simulation results of three types of forwarding which are unicast, geocast and geodirectional-cast. The finding shows geodirectional-cast improves throughput and consumes acceptable power compared to unicast and geocast forwarding.