International Conference on Computer and Communication Engineering (ICCCE 2012), 3-5 July 2012, Kuala Lumpur, Malaysia 978-1-4673-0479-5/12/$31.00 ©2012 IEEE Abstract— Heterogeneous networks are developed to allow communication devices to access the wireless network using different access technologies. In heterogeneous networks, group of networks can be used to provide particular services. Every service can be delivered to the user using the optimum network for that service. Mobile positioning is an important service that can be offered by heterogeneous networks by using the resources of the cellular system to determine the location of a mobile station. However, the accuracy of the localization is subjected to the Location Determination Techniques (LDT) adopted such as Time-of-Arrival (TOA), Time Difference-of- Arrival (TDOA) and Enhanced Observed-Time-Difference (E- OTD), and signal hearability. This work analyzes appropriate LDT and proposing a hybrid algorithm under low hearability condition for heterogeneous network. Two simulations have been implemented for these purposes, the first one is single layer cellular network system which is used to evaluate and compare various LDT techniques under different mobility models. The second simulation has been implemented to evaluate the proposed hybrid algorithm and compare it with several LDT techniques considering the accuracy of location measurements. The results show that the LDT error for hybrid technique is better as compare to TDOA and E-OTD at 67% and 95% of the cumulative density functions (CDF). Keyword—Location Based Services (LBS), Location Determination Technique (LDT), heterogeneous network, and hearability. I. INTRODUCTION The mobile communication market has grown rapidly over the past 10 years, but the market may reach saturation in the foreseeable future. More flexible mobile networks able to meet various user demands and create new market openings are needed for further growth. Access to networked data and information services has taken on an ever increasing importance to users for business, entertainment, and social networking applications. Users want high speed, high-reliability, and high-quality access to these information services to be ubiquitous and available when they are fully mobile. Having these services available in a mobile environment also provides additional opportunities for service providers to enrich their offerings with location-based services [10]. One of the fundamental components common to all location-based services (LBSs) is the use of positioning technologies to track the movement of mobile clients and to deliver information services to the mobile clients on the move at the right time and right location. Therefore, the effective use of positioning technologies can have a significant impact on the performance, reliability, security, and privacy of LBSs, systems, and applications. The next section of this paper will organize as follows. Section II describes single layer cellular network. Section III will discuss about multilayer heterogeneous network. In Section IV, methodology of this research is introduced, including the major workflow of the activities. Section V presents how the simulation is done, and the result will be discussed in section VI. Finally a conclusion is proposed in section VII. II. SINGLE LAYER CELLULAR NETWORK LDT is a location determination technology which helps to determine the location of a mobile device. This simulation has been implemented to evaluate each LDT technique mentioned earlier solely in a single layer heterogeneous platform under different mobility models. The user has the ability to choose one of the pre-built networks in the program which are GSM900, GSM1800, WiMAX, and WCDMA with predefined specifications. Otherwise, the user can specify custom specifications for a user defined single layer cellular network. Figure 1 shows five options a user can choose from. The last option i.e. custom topology, activate four text box to provide network specifications. The required specifications are the coordinates of first base station, base station radius, and number of base stations. Figure 1: Single layer cellular network graphical interface Hybrid Location Determination Techniques in Heterogeneous Network M. Ismail 1,2 , F. Alawe 1 , W. Al-alimi 1 , R. Nordin 1 , and S. Bohanudin 1 1 Department of Electrical, Electronics and System Engineering, 2 Institut Sains Angkasa Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor, Malaysia. {fta, mahamod, adee,sbrh63}@eng.ukm.my, hi2me1000@yahoo.com 836 Authorized licensed use limited to: UNIVERSITY OF KENT. Downloaded on February 24,2024 at 11:02:06 UTC from IEEE Xplore. Restrictions apply.