High Speed Mobility Management Performance in a Real LTE Scenario

Abstract

This paper discusses the mobility management for high-speed users, which is a crucial challenge for all mobile operators, especially when users are moving vertically across different network technologies. Mobility, also known as seamless connectivity, is directly influencing the quality of service (QoS). Mobility management-Handover (HO) performance was evaluated by field measurements of a Long Term Evolution (LTE) network of a mobile operator in the Middle East. Drive test measurements were used to analyze the results of different high-speed scenarios. User Equipment (UE) with high speed of 80-140km/h causes a high risk of failure of seamless connectivity as the HO procedure timing is longer than for UE with smaller speed. HO failure and call drop may occur when UE is moving with high speed across two adjacent cells in highways. During measurements, HO failure occurred when UE speed was 140km/h, and HO preparation timing increased when UE speed increased.

Real-time high-speed mobility management

“…While trying to make the cell selection/reselection during the ideal mode and the HO decision in the connected mode, RSRP is viewed as one of the main measurement parameters. As stated in [16], the signal strength variation would be between -80 to -105 dBm as configured in most mobile operators, whereas the classic 3GPP range is somewhere between -44 and -140 dBm [17], so it is clear that mobile operators are attempting to raise their rules to ensure high service quality, to avoid regulatory parties' penalties due to bad customer experience and to meet their obligations.…”

“…Bai et al [10] studied velocity and quality of service (QoS) for evolved node B (eNB) and femtocell handover to minimize unnecessary handoff. The UE velocity is categorized into three classes (0-15), (15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30), and (>30) km/h to prevent unsuccessful calls. The algorithm neglects services that are not in real-time.…”

A Fairness-based Cell Selection Mechanism for Ultra-Dense Networks (UDNs)

“…In addition, it could accommodate changes in network topology and channel conditions. In [31], the QoS of high-speed mobility in LTE was discussed, measuring handover performance while UEs moved at high speed. The results were classified into multiple classes according to UE speed, showing that it could be determined when handover could fail and the call could be dropped.…”

A Novel Drone-based Search and Rescue System using Bluetooth Low Energy Technology

“…There are various fundamental concepts when considering the positioning of BLE devices. The simplest approach of positioning is determining if both the target and the locator are within the radio coverage range, while providing a binary decision about their presence within that range [23]. In order to determine the distance between devices in free space, the following equation that relates distance (d) and the Received Signal Strength Indicator (RSSI) was utilized.…”

“…In some commercial applications, such as the iBeacon, it is recommended that the advertising signal intervals should be set below 100ms, when the tag is operated by a coin cell battery for maximizing the battery life to a few months. In addition, when the intervals are set just below 1000ms the battery may last up to 3 years [23].…”