RSS-Based Localization and Mobility Evaluation Using a Single NB-IoT Cell

Low Power Wide Area Networks (LPWAN) have the ability to localize a mobile transmitter using signals of opportunity, as a low power and low cost alternative to satellite-based solutions. In this paper, we evaluate the accuracy of three localization approaches based on the Received Signal Strength (RSS). More specifically, the performance of a proximity, range-based and optimized fingerprint-based algorithm is evaluated in a large-scale urban environment using a public Narrowband Internet of Things (NB-IoT) network. The results show a mean location estimation error of 340, 320 and 204 m, respectively. During the measurement campaign, we discovered a mobility issue in NB-IoT. In contrast to other LPWAN and cellular technologies which use multiple gateways or cells to locate a device, only a single cell antenna can be used for RSS-based localization in NB-IoT. Therefore, we address this limitation in the current NB-IoT hardware and software by studying the mobility of the cellular-based 3GPP standard in a localization context. Experimental results show that the lack of handover support leads to increased cell reselection time and poor cell sector reliability, which in turn results in reduced localization performance.

IMPROVEMENT OF CALL SETUP TIME DURING CIRCUIT SWITCHED FALLBACK

In handover procedure, target cell would be prepared and UE will move on target cell based on the configuration sent by source eNodeB to User Equipment. Cell Reselection happens only when the user equipment (or Mobile Phone) is in Idle MODE, and the User Equipment needs to go a more appropriate cell. The main feature of CSFB Ps handover does not interrupt data transfer when switching from Long Term Evolution to UTRAN/GSM. After switching to 3G is already in connected mode it does not waste time to switch to connected mode. This feature let us improve call setup time when we make call in LTE.

UE-Initiated Cell Reselection Game for Cell Load Balancing in a Wireless Network

A user changes its serving cell if the quality of experience (QoE) provided by the current serving cell is not satisfactory. Since users reselect cells to increase their QoEs selfishly, the system resource efficiency can be deteriorated and a system can be unstable if users are not driven to cooperate appropriately. In this paper, inspired by the minority game (MG) model, we design a UE-initiated cell reselection policy. The MG has a salient characteristic that the number of players who win the game converges to a prespecified value even though players act selfishly without knowing the actions taken by the other players. Using the MG model, we devise a rule by which each UE plays a cell reselection game. We also design a criterion that a system controller uses to determine the result of a game and public information sent by a system controller to induce implicit cooperation among UEs. The simulation results show that compared with noncooperative method the proposed method increases not only the system performance, such as cell load balance index and system utility, but also the performance of UEs in terms of a downlink data rate and an outage probability received from a system.

The Development of RRM Conformance Test in TD-LTE Idle_State

In order for the RRM conformance of implementation in TD-LTE system idle_state, taking inter-frequency cell reselection procedure as the point of penetration, a new testing scheme is designed by developing testing and test control notation version 3(TTCN-3) test case to verify the RRM conformance. Furthermore, the test case is operated on the TTworkbench developed by German Testing tech. It also generates test execution flow chart to check the RRM conformance of idle_state functions.