9 results on '"mobile relay node"'
Search Results
2. Uplink Reference Signals for Power-Efficient Handover in Cellular Networks With Mobile Relays
- Author
-
Muhammad Tayyab, George P. Koudouridis, Xavier Gelabert, and Riku Jantti
- Subjects
Uplink reference signal ,sounding reference signal ,handover ,3GPP cellular networks (LTE/NR) ,mobile relay node ,simulation ,Electrical engineering. Electronics. Nuclear engineering ,TK1-9971 - Abstract
When a vehicle moves from one base station (BS) to another, a large number of on-board user equipments (UE) may simultaneously and individually perform a handover (HO) procedure, resulting in increased HO overheads. A mobile relay node (MRN), connected via a wireless backhaul to a donor base station (DBS), is deployed on the rooftop of a bus to improve the link quality and reduce the associated HO overhead via group mobility. However, at moderate to high speeds, the on-board UEs can still suffer from frequent HOs due to the MRN failing to HO to a new DBS using the legacy downlink measurement-based HO (DL-HO) method. As a consequence, the connection towards all associated mobile users will be lost which poses tight reliability requirements on the backhaul link to avoid becoming a single point of failure (SPoF). In order to improve the reliability during group handover, in this work, we propose an uplink reference signal (UL RS) based HO procedure (coined as UL-HO) for the MRN which relies on the existing sounding reference signal in long term evolution (LTE) /new radio (NR). In the proposed scheme, and unlike the legacy DL-HO procedure in LTE/NR, the measurement report (MeasReport) transmission is not required between MRN and the DBS, therefore the HO delay can be reduced, decreasing the SPoF chances and thus, uninterrupted services can be provided to on-board UEs. We investigate the gain in terms of HO rate, HO failure rate, ping-pong rate and power consumption (both at the UE and the BS). Performance evaluations demonstrate that the proposed UL-HO scheme outperforms the legacy DL-HO scheme in current cellular networks. more...
- Published
- 2021
- Full Text
- View/download PDF
Catalog
3. FTGPHA: Fixed-Trajectory Group Pre-Handover Authentication Mechanism for Mobile Relays in 5G High-Speed Rail Networks.
- Author
-
Ma, Ruhui, Cao, Jin, Feng, Dengguo, Li, Hui, and He, Shiyang
- Subjects
- *
HIGH speed trains , *SOFTWARE-defined networking , *DATA transmission systems - Abstract
For high-speed rail networks, data transmission suffers from severe penetration loss and when the train moves from one base station to another, a large number of User Equipments (UEs) on board carry out the handover authentication procedure simultaneously, which incurs a lot of handover overheads. The introduction of Mobile Relay Node (MRN) can improve the link quality and decrease the handover overheads. However, MRNs still suffer from several protocol attacks and frequent handovers and thus, the introduction of MRNs deteriorates the handover success rate and handover performance. At the same time, considering the diversity of future 5G high-speed rail networks, in this paper, we propose two fixed-trajectory group pre-handover authentication schemes for MRN: the first proposed scheme FTGPHA1 which establishes most of the important security properties and costs low handover overheads, and the second proposed scheme FTGPHA2 which furnishes better security properties than the first one. In these two schemes, since all of the MRNs in the same train and the next base station can accomplish the handover authentication with the help of the donor software defined networking controller before the MRN arrives, the handover delay can be ignored and thus, uninterrupted services can be provided for UEs on board. The security and performance evaluations demonstrate that the two proposed schemes outperform other related schemes. [ABSTRACT FROM AUTHOR] more...
- Published
- 2020
- Full Text
- View/download PDF
4. A Two-Hop MIMO Relay Architecture Using LTE and Millimeter Wave Bands in High-Speed Trains.
- Author
-
Oliva Sanchez, Jose David and Alonso, Jose I.
- Subjects
- *
MIMO systems , *LONG-Term Evolution (Telecommunications) , *MILLIMETER waves , *HIGH speed trains , *ANTENNAS (Electronics) - Abstract
In this paper, a novel two-hop relay architecture using mobile relay nodes (MRN) technology for high-speed trains is presented. In this architecture, a long-term evolution advanced (LTE-A) link in sub-6 GHz bands is established between the Donor-eNB (DeNB) and the MRNs mounted on the roof of the train and another in millimeter Wave (mmWave) bands between the MRN and the user equipment (UE) terminals inside the train. Moreover, the multiple-input multiple-output (MIMO) channel is exploited between the DeNB and the UEs to enhance channel capacity. Different relay structures—several relays in a train carriage and a single relay with multiple antennas—and different types of relays—amplify-and-forward and decode-and-forward (DF)—are studied. Ultimately, performance analysis is studied and discussed by means of a downlink-level simulator with accurate channel models. Furthermore, multiuser transmission and conventional user scheduling algorithms are added to obtain a more realistic simulator. A new algorithm for one of the structures and the DF relay is proposed. This paper will examine how to provide broadband data access to train passengers in high-speed environments by validating a new architecture, which takes advantage of MIMO techniques, mobile relays, and millimeter bands. [ABSTRACT FROM AUTHOR] more...
- Published
- 2019
- Full Text
- View/download PDF
5. Mobile Data Collection Networks for Wireless Sensors
- Author
-
Li, Kai, Hua, Kien A., Dziech, Andrzej, editor, and Czyżewski, Andrzej, editor
- Published
- 2012
- Full Text
- View/download PDF
6. Self-Optimization of Handover Parameters for Long-Term Evolution with Dual Wireless Mobile Relay Nodes
- Author
-
Battulga Davaasambuu, Keping Yu, and Takuro Sato
- Subjects
self-optimization ,handover parameter ,mobile relay node ,cell individual offset ,hysteresis ,Information technology ,T58.5-58.64 - Abstract
In recent years, train passengers have been transferring increasing amounts of data using mobile devices. Wireless networks with mobile relay nodes support broadband wireless communications for passengers of such vehicles using backhaul links. However, the mobility management entity reuses the handover of existing user equipment, resulting in the handover of the Long-Term Evolution network being unsuitable for user equipment within the cabins of vehicles traveling at high speed. In this paper, we propose a self-optimizing handover hysteresis scheme with dual mobile relay nodes for wireless networks in high-speed mobile environments. The proposed mechanism tunes the hysteresis and cell individual offset handover parameters based on the velocity of the vehicle and the handover performance indicator, which affects the handover triggering decision and performance. The results of simulations conducted in which the performance of the proposed scheme was compared to that of an existing scheme show that the proposed scheme can reduce the number of radio link failures and service interruptions during handover procedures. more...
- Published
- 2015
- Full Text
- View/download PDF
7. On Signal Detection for OSTBC-Based Amplify-and-Forward Cooperative Relaying System Over Time Selective Channel.
- Author
-
Patra, Jyoti P. and Singh, Poonam
- Subjects
SIGNAL detection ,ORTHOGONAL codes ,BLOCK codes ,WIRELESS communications ,SIGNAL-to-noise ratio - Abstract
The orthogonal space-time block code (OSTBC) and cooperative relaying schemes are the two major spatial diversity techniques to achieve high link reliability in any wireless communication system. Typically, the OSTBC based cooperative amplify-and-forward relaying system achieves optimal diversity gain with simple linear decoding by assuming that the channels remain quasi-static during the length of the Alamouti code-word symbol periods. However, due to time selective fading or relay node’s mobility, the quasi-static assumptions does not hold good and causes severe error floor in the system. In this paper, at first, we have investigated various conventional signal detection methods to improve the system performance which include Alamouti and quasi-ML detection (QMLD) methods. Then, we derive the exact closed-form signal-to-interference-plus-noise ratio expression for the Alamouti method and signal-to-noise ratio for the QMLD method. Based on this performance analysis, we propose a decision feedback detection (DFD) which is a hybrid of Alamouti and QMLD methods. The simulation results show that the proposed DFD method significantly outperforms the conventional QMLD method under high mobility channel environment. [ABSTRACT FROM AUTHOR] more...
- Published
- 2018
- Full Text
- View/download PDF
8. Self-Optimization of Handover Parameters for Long-Term Evolution with Dual Wireless Mobile Relay Nodes
- Author
-
Keping Yu, Battulga Davaasambuu, and Takuro Sato
- Subjects
cell individual offset ,lcsh:T58.5-58.64 ,Computer Networks and Communications ,Computer science ,business.industry ,Wireless network ,lcsh:Information technology ,Real-time computing ,ComputerSystemsOrganization_COMPUTER-COMMUNICATIONNETWORKS ,Soft handover ,mobile relay node ,Self-optimization ,Backhaul (telecommunications) ,Handover ,User equipment ,hysteresis ,Wireless ,business ,Mobility management ,handover parameter ,Computer network ,self-optimization - Abstract
In recent years, train passengers have been transferring increasing amounts of data using mobile devices. Wireless networks with mobile relay nodes support broadband wireless communications for passengers of such vehicles using backhaul links. However, the mobility management entity reuses the handover of existing user equipment, resulting in the handover of the Long-Term Evolution network being unsuitable for user equipment within the cabins of vehicles traveling at high speed. In this paper, we propose a self-optimizing handover hysteresis scheme with dual mobile relay nodes for wireless networks in high-speed mobile environments. The proposed mechanism tunes the hysteresis and cell individual offset handover parameters based on the velocity of the vehicle and the handover performance indicator, which affects the handover triggering decision and performance. The results of simulations conducted in which the performance of the proposed scheme was compared to that of an existing scheme show that the proposed scheme can reduce the number of radio link failures and service interruptions during handover procedures. more...
- Published
- 2015
9. Analysis of Optimal Strategies to Minimize Message Delay in Mobile Opportunistic Sensor Networks
- Author
-
Jun, Jung Hyun
- Subjects
- Computer Science, opportunistic network, mobile relay node, average message delay, optimal handover policy, wireless sensor network, grid topology
- Abstract
Wireless sensor networks (WSNs) are autonomous and self-healing networks of small battery powered sensors. Besides sensing their physical environments, these sensors are capable of communicate wirelessly, store, and compute data locally. The small size and its capability attract academics as well as industry for real-time monitoring of an area for potential events like wild fire, intruders, and hazardous gas. Since multi-hop communications from sources to sink node were unavoidable in WSNs, it is hard to achieve a longer life time.To reduce multi-hop communication, the idea of using mobile nodes as relay nodes which collect data and deliver it to sink, was introduced to WSNs. In addition to life time improvement, the mobile relay nodes can also keep wireless bandwidth capacity to a constant level while the node density is high. The mobile relay nodes moves independently and random from the perspective of WSNs. Mobile Opportunistic sensor Network (MOsN) specifically denotes overlays of the mobile opportunistic network on top of a static wireless sensor network where the time taken for relay nodes to deliver the data from static sensors to sink is completely opportunistic and unbounded. However, many applications related to security, emergency, and bio-hazard cannot tolerate this unbounded message delay. So we begin by analyzing the average time taken for relay nodes to deliver the message to sink in MOsN by modeling the delivery of message as a randomly moving particle with certain biasness towards the sink. The result shows this delay is a function of the message bias level and distance d from the sink to origin of message. The sink as placed in the center of tilted grid with the radius of D and the message bias level α which varies [0, 1], the delay can vary from Ο(d) to Ο(D log d) to Ο(D² log d). Based on this result, we propose an heuristic algorithm which forward the data to other relay nodes if it has the bias level larger than a threshold 1/(2x+1), where x is distance of relay node carrying message to the sink.Finally, we deduced that the lower average message delay can be achieved by a static sensor wait for a relay node with its bias level higher than some threshold for its message delivery. Before we delve into optimal message handover policy, the movement of relay nodes modeled as a directed random walk with biases in their mobility. This bias random mobility model well represents the network of multiple independent but not identically moving relay. The relationship between the message bias level and mobility bias level is derived from a help of the simulation results. The optimal message handover policy based on the observed mobility bias level is proposed for static sensors at different locations when the inter-arrival time of relay nodes to a given static sensor is close to a constant. We also propose an optimal relay node selection algorithm in the case of inter-arriving time of relay nodes are linearly increasing. more...
- Published
- 2011
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.