Handoff for wireless networks with mobile relay stations
28 Mar 2011-pp 826-831
TL;DR: The proposed handoff algorithm can significantly improve the handoff successful rate when the mobile relay station changes its moving patterns and a new handoff decision algorithm based on the relative velocities of user equipment to the serving access point and the target AP is proposed.
Abstract: Wireless Relay networks have become very important technologies in the future wireless systems. Current research works mostly focus on scenarios where relay stations are either stationary or mobile with uniform velocity. However, in many applications, relay stations are mobile with irregular patterns. In particular, when mobile relay stations (MRSs) are deployed to complement the cellular systems, many issues such as handoff should be carefully investigated. In this paper, we focus on the handoff problem and propose a new handoff decision algorithm based on the relative velocities of user equipment (UE) to the serving access point (AP) and the target AP. We have show that the proposed handoff algorithm can significantly improve the handoff successful rate when the mobile relay station changes its moving patterns.
Citations
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TL;DR: An enhanced handover scheme is proposed, which contains an enhanced measurement procedure, which can accelerate the measurement procedure when the mobile relay knows that the train is moving toward some neighbor DeNBs, and a group in-network handover procedure which can aggregate similar in network handover procedures in the core network.
Abstract: Recently, the mobile relay technique has been discussed to support communication services for Long-Term Evolution Advanced (LTE-A) high-speed rail networks. In the network, there are several mobile relays in a train. User equipment (UE) devices connect to in-car mobile relays instead of outside evolved NodeBs (eNBs). Mobile relays establish backhaul links with the serving donor eNBs (DeNBs) and coordinate control and data flows for UE devices. Since the train travels in high speed, mobile relays suffer from frequent handovers between DeNBs. We observe that the defined handover procedures in LTE-A specifications may incur message overhead and lengthen handover time. In this paper, we propose an enhanced handover scheme, which contains two procedures. The first procedure is an enhanced measurement procedure, which can accelerate the measurement procedure when the mobile relay knows that the train is moving toward some neighbor DeNBs. The second procedure is a group in-network handover procedure, which can aggregate similar in network handover procedures in the core network. Performance evaluations indicate that our design can conserve both time and messages when handover.
101 citations
Cites background from "Handoff for wireless networks with ..."
...In [34], a handover scheme for UE devices, which are located on...
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...Next, [11] and [32]–[34] propose handover schemes without...
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17 Dec 2015
TL;DR: This paper study and simulate, using MATLAB, handover in LTE - R system, choosing A3 event handover algorithm based on measuring Reference signal Received Power (RSRP) and the impact of changing both velocity and transmitted power is simulated.
Abstract: Railway wireless communication has become an indispensable part to provide the reliability and safety of the railway operation as well as the improved railway services. GSM for Railway (GSM-R) system is a widely used means of railway communication, its commercial success are fully explained that GSM-R system has maturity and reliability. Along with the developments of the high-speed railway, higher and higher technical requirements for the high-speed railway mobile communication system are raised. GSM-R has shown many limitations in high speed, high-quality transmission. Therefore, long term evolution (LTE), is basically confirmed as the next generation railway wireless communication technology, namely LTE — R. As the fourth generation, LTE — R provides a high transmission speed and high mobility to the user. As trains move with relatively high speed, they suffer from many handovers. In this paper we study and simulate, using MATLAB, handover in LTE — R system. We choose A3 event handover algorithm based on measuring Reference signal Received Power (RSRP). The impact of changing both velocity and transmitted power is also simulated.
14 citations
TL;DR: The result shows that the proposed method adjusts to various network topologies and provides better achievable bandwidth than both the SINR-based method and the FPA method.
Abstract: The Cucker–Smale flocking model is designed to analyze the velocity and position-control mechanisms in a group of living individuals, such as a flock of birds. In this model, each agent (a bird or fish) adjusts its velocity according to its own velocity and the weighted mean of the relative velocities of the other members of the flock. We herein focus on the simple, distributed, and autonomous nature of the flocking model and apply its operating principles to fair resource allocation for vehicle-mounted mobile relays (VMRs) by considering their need for distributed fair resource allocation in various network topologies. By adaptively adjusting the VMR transmission power, the proposed method effectively alleviates the interference between users in vehicles and users directly connected to the base station. We evaluate the performance of the proposed method in the context of the IEEE 802.16j based system. The achievable bandwidth performance of the proposed method is evaluated relative to that of both the fixed power allocation (FPA) method and the signal-to-interference plus noise ratio (SINR)-based transmit power control method. The result shows that the proposed method adjusts to various network topologies and provides better achievable bandwidth than both the SINR-based method and the FPA method.
14 citations
Cites methods from "Handoff for wireless networks with ..."
...An optimal handover scheme, in which the handover interval is adjusted according to the vehicle speed, was proposed in [12]....
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Patent•
26 Mar 2014TL;DR: In this article, a method in a mobile terminal is disclosed for determining whether or not to transmit a connection request for a connection between the mobile terminal and a base station, where the base station is moving.
Abstract: A method in a mobile terminal is disclosed for determining whether or not to transmit a connection request for a connection between the mobile terminal and a base station, where the base station is moving When the mobile terminal is detecting the base station, the mobile terminal is determining (302) an indication of a relative speed between the mobile terminal and the detected base station The mobile terminal is then determining (308) whether or not to transmit the connection request to the base station It is determined to transmit the connection request when the determined indication of the relative speed between the mobile terminal and the base station indicates that the relative speed is below a first threshold
7 citations
Patent•
26 Mar 2014TL;DR: In this paper, a method in a base station is disclosed for determining connection establishment between the base station and a mobile terminal, where the mobile terminal is moving, based on a determination as to whether the base stations and the mobile terminals move jointly.
Abstract: A method in a base station is disclosed for determining connection establishment between the base station and a mobile terminal, where the base station is moving. When the base station receives a first connection request, the base station refrains (202) from establishing a connection between the base station and the mobile terminal. When the base station receives a second connection request from the mobile terminal within a certain time period from the first connection request, the base station determines (209) whether or not to establish the connection between the base station and the mobile terminal based on a determination as to whether the base station and the mobile terminal move jointly.
4 citations
References
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TL;DR: An overview of important topics and applications in the context of relaying covers different approaches to exploiting the benefits of multihop communications via relays, such as solutions for radio range extension in mobile and wireless broadband cellular networks and solutions to combat shadowing at high radio frequencies.
Abstract: In recent years, there has been an upsurge of interest in multihop-augmented infrastructure-based networks in both the industry and academia, such as the seed concept in 3GPP, mesh networks in IEEE 802.16, and converge extension of HiperLAN/2 through relays or user-cooperative diversity mesh networks. This article, a synopsis of numerous contributions to the working group 4 of the wireless world research forum and other research work, presents an overview of important topics and applications in the context of relaying. It covers different approaches to exploiting the benefits of multihop communications via relays, such as solutions for radio range extension in mobile and wireless broadband cellular networks (trading range for capacity), and solutions to combat shadowing at high radio frequencies. Furthermore, relaying is presented as a means to reduce infrastructure deployment costs. It is also shown that through the exploitation of spatial diversity, multihop relaying can enhance capacity in cellular networks. We wish to emphasize that while this article focuses on fixed relays, many of the concepts presented can also be applied to systems with moving relays.
1,907 citations
"Handoff for wireless networks with ..." refers background in this paper
...Thus, the deployment of relay station (RS) becomes an important strategy in increasing data rate while preserving the coverage that cellular systems bring to us in the future wireless systems [8]....
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14 Sep 2003
TL;DR: This paper proposes the Unified Cellular and Ad-Hoc Network (UCAN) architecture for enhancing cell throughput, while maintaining fairness, and refine the 3G base station scheduling algorithm so that the throughput gains of active clients are distributed proportional to their average channel rate.
Abstract: In third-generation (3G) wireless data networks, mobile users experiencing poor channel quality usually have low data-rate connections with the base-station. Providing service to low data-rate users is required for maintaining fairness, but at the cost of reducing the cell's aggregate throughput. In this paper, we propose the Unified Cellular and Ad-Hoc Network (UCAN) architecture for enhancing cell throughput, while maintaining fairness. In UCAN, a mobile client has both 3G cellular link and IEEE 802.11-based peer-to-peer links. The 3G base station forwards packets for destination clients with poor channel quality to proxy clients with better channel quality. The proxy clients then use an ad-hoc network composed of other mobile clients and IEEE 802.11 wireless links to forward the packets to the appropriate destinations, thereby improving cell throughput. We refine the 3G base station scheduling algorithm so that the throughput gains of active clients are distributed proportional to their average channel rate, thereby maintaining fairness. With the UCAN architecture in place, we propose novel greedy and on-demand protocols for proxy discovery and ad-hoc routing that explicitly leverage the existence of the 3G infrastructure to reduce complexity and improve reliability. We further propose a secure crediting mechanism to motivate users to participate in relaying packets for others. Through extensive simulations with HDR and IEEE 802.11b, we show that the UCAN architecture can improve individual user's throughput by up to 310% and the aggregate throughput of the HDR downlink by up to 60%.
509 citations
"Handoff for wireless networks with ..." refers background in this paper
...The envisioned applications of relaying stations in the traditional cellular systems lead to the multi-hop cellular networks [13]....
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01 Sep 1994
TL;DR: An overview of the wireless data field is presented, emphasizing three major elements: technologies utilized in existing and currently planned wireless data services, issues related to the performance of these systems, and discernible trends in the continuing development of wireless data systems.
Abstract: Wireless data services and systems represent a rapidly growing and increasingly important segment of the communications industry. In the paper the authors present an overview of this field, emphasizing three major elements: (1) technologies utilized in existing and currently planned wireless data services, (2) issues related to the performance of these systems, and (3) discernible trends in the continuing development of wireless data systems. While the wireless data industry is becoming increasingly diverse and fragmented, one can identify a few mainstreams which relate directly to users requirement for data services. On one hand, there are requirements for relatively low-speed data services supporting mobile users over wide geographical areas, as provided by mobile data networks. On the other hand, there are requirements for high-speed data services in local areas, as provided by wireless LANs. The system-level issues are somewhat different for these two categories of services, and this has led to different technology choices in the two domains, which the authors discuss in the paper. >
359 citations
TL;DR: The design enhancements have produced a set of highly efficient schemes that achieve significant reduction in handoff blocking rates while only incurring remarkably small increases in the new call blocking rates.
Abstract: We propose and evaluate new schemes for channel reservation motivated by the rapidly evolving technology of mobile positioning. The schemes, called predictive channel reservation (PCR), work by sending reservation requests to neighboring cells based on extrapolating the motion of mobile stations (MSs). A number of design enhancements are incorporated to minimize the effect of false reservations and to improve the throughput of the cellular system. These enhancements include: (1) reservation pooling; (2) queuing of reservation requests; (3) hybrid approach for integrating guard channels (GCs); and (4) using a threshold distance (TD) to control the timing of reservation requests. The design enhancements have produced a set of highly efficient schemes that achieve significant reduction in handoff blocking rates while only incurring remarkably small increases in the new call blocking rates. The PCR approach has also been used to solve the MINBLOCK optimization problem and has given significant improvement over the fractional guard channel (FGC) protocol. Detailed performance results of the different variations of the PCR scheme and comparisons with conventional channel reservation schemes are presented. An analytical Markov model for the hybrid predictive version of the scheme is developed and its applicability and numerical results are discussed.
238 citations
"Handoff for wireless networks with ..." refers background in this paper
...By predicting which cell is the target cell based on the direction and velocity of a UE, the target cell can prepare the handoff for the UE in advance [7]....
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12 Oct 1993
TL;DR: Simulation results show that velocity adaptive corner detecting handoff algorithms yield faster and more consistent handoff performance than traditional methods.
Abstract: Fast handoff algorithms for urban microcells using velocity adaptation and corner detection are presented. Three velocity estimators are compared with respect to their accuracy, sensitivity to non-isotropic scattering, capability of detecting when a mobile turns a corner, and response time in typical microcell environments. Simulation results show that velocity adaptive corner detecting handoff algorithms yield faster and more consistent handoff performance than traditional methods.
129 citations
"Handoff for wireless networks with ..." refers background in this paper
...The effects of the terminals or UEs moving velocities on handoff performance have been studied in [5] [6]....
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