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Author

Yilin Song

Bio: Yilin Song is an academic researcher from Chinese Academy of Sciences. The author has contributed to research in topics: Quality of service & Handover. The author has an hindex of 4, co-authored 8 publications receiving 35 citations.

Papers
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Proceedings ArticleDOI
14 May 2007
TL;DR: A dynamic, prediction-based, multi-class, adaptive bandwidth reservation scheme for IEEE 802.16 (WiMAX) networks that guarantees that the real-time sessions have higher priorities than non real- time sessions and that handover sessions haveHigher priorities than new sessions.
Abstract: According to the characteristics and QoS requirements of different types of service flows, this paper proposes a dynamic, prediction-based, multi-class, adaptive bandwidth reservation scheme for IEEE 802.16 (WiMAX) networks. The scheme adopts different bandwidth reservation and admission control policies to different types of service flows and therefore guarantees that the real-time sessions have higher priorities than non real-time sessions and that handover sessions have higher priorities than new sessions. In addition, a bandwidth reservation adaptation algorithm is also proposed. The algorithm adjusts the amount of bandwidth reserved for handover sessions according to the current network conditions thus creating a balance between new session blocking rate and handover session dropping rate.

12 citations

Proceedings ArticleDOI
08 Dec 2008
TL;DR: This paper presents a new probabilistic methodology to estimate AB under "non busy assumption", and proposes a metric to weigh the busyness of a network path based on the distribution of output probe gap.
Abstract: Previous Probe Gap Model (PGM) based available bandwidth (AB) estimation methods all request the "busy assumption" that probing packet pairs should be in the same busy period when transmitted on bottleneck link, which is hard to satisfy especially for the low utilization path. In this paper, we first present a new probabilistic methodology to estimate AB under "non busy assumption". The methodology is quite accurate on the low utilization network path. Secondly, we propose a metric to weigh the busyness of a network path based on the distribution of output probe gap. Using the metric, we combine our new methodology and previous methodology, and present a new AB estimation method called Adaptive Available Bandwidth Estimation (A_ABE) which is fit for both low utilization and high utilization paths. We use NS-2 simulation and reproduce traffic from real Internet links to evaluate A_ABE. Compared with previous methods, A_ABE shows its advantages in terms of accuracy, overhead, and also the robustness when confronted with non-persistent cross traffic in multiple hop situations.

11 citations

Proceedings ArticleDOI
03 Aug 2009
TL;DR: The key issues affecting the handover latency of the predictive FMIPv6 in IEEE 802.11 WLANs are the lack of assistance from the network entities, the ambiguous link layer triggering time and the inefficient interaction between the link layer and the network layer.
Abstract: Experiments show that FMIPv6 may suffer long handover latency even in the predictive mode in the real IEEE 802.11 based WLANs. To figure out the latency reason and identify potential enhancement of FMIPv6, we analyze the handover latency of the predictive FMIPv6 from a cross layer perspective using data collected in a real IEEE 802.11 test-bed. We find that the key issues affecting the handover latency of the predictive FMIPv6 in IEEE 802.11 WLANs are the lack of assistance from the network entities, the ambiguous link layer triggering time and the inefficient interaction between the link layer and the network layer. And FMIPv6 can provide fast handover with no interruptions on the upper layer applications in IEEE 802.11 WLANs through some enhancements, which can resolve the above three issues.

5 citations

Journal ArticleDOI
TL;DR: Fast RSVP, compared with existing methods of resource reservation in mobile environments, performs better in terms of packet delay and throughput during hand over, QoS recovery time after handover, resource reservation cost, handover session forced termination rate and overall session completion rate.
Abstract: In recent years, with the development of mobile communication technologies and the increase of available wireless transmission bandwidth, deploying multimedia services in next generation mobile IPv6 networks has become an inevitable trend. RSVP (resource reservation protocol) proposed by the IETF is designed for hardwired and fixed networks and can not be used in mobile environments. This paper proposes a protocol, called Fast RSVP, to reserve resources for mobile IPv6. The protocol adopts a cross-layer design approach where two modules (RSVP module and Mobile IPv6 module) at different layers cooperate with each other. Fast RSVP divides a handover process with QoS guarantees into two stages: (1) setup of the resource reservation neighbor tunnel and (2) resource reservation on the optimized route. It can help a mobile node realize fast handover with QoS guarantees as well as avoid resource wasting by triangular routes, advanced reservations and duplicate reservations. In addition, fast RSVP reserves "guard channels" for handover sessions, thus greatly reducing the handover session forced termination rate while maintaining high performance of the network. Based on extensive performance analysis and simulations, Fast RSVP, compared with existing methods of resource reservation in mobile environments, performs better in terms of packet delay and throughput during handover, QoS recovery time after handover, resource reservation cost, handover session forced termination rate and overall session completion rate.

4 citations

Proceedings ArticleDOI
15 Oct 2007
TL;DR: A new cross layer scheme (fast RSVP) to reserve resources for mobile IPv6, which allows a mobile node to realize fast handover with QoS guarantees and distinguishes different types of reservation requests, greatly reducing the handover session forced termination rate while maintaining high performance of the network.
Abstract: This paper proposes a new cross layer scheme (fast RSVP) to reserve resources for mobile IPv6. Through the cooperation of mobile IP and RSVP modules, fast RSVP includes a number of mechanisms such as advance resource reservation on neighbor tunnels, resource reservation on optimized routes, resource reservation for handover sessions (guard channel) etc. Network simulation results show that our scheme, compared with other traditional ways to reserve resources in mobile environments, has the following advantages: (1) it allows a mobile node to realize fast handover with QoS guarantees; (2) it avoids resource wasting caused by triangular routes and duplicate reservations; (3) it distinguishes different types of reservation requests, greatly reducing the handover session forced termination rate while maintaining high performance of the network.

2 citations


Cited by
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Journal ArticleDOI
TL;DR: It is shown how the analysis of user behavior, in terms of mobility, can be exploited to enhance QoS levels in current communications among mobile hosts and base stations (coverage cells, in general).
Abstract: Nowadays, interest in mobile communications is growing rapidly due to the high level of device development, which permits the achievement of good objectives in terms of quality of service (QoS) for user satisfaction during active data flows. The increasing mobile client populations use different mobile devices to access the wireless medium and many applications are being developed to satisfy eager client requirements. Independently on the considered architecture (WLAN, UMTS, LTE, etc.), mobility represents a great advantage for user comfort, but it needs to be managed in an adequate manner in order to avoid service disruptions or unacceptable degradation of the perceived quality. In this paper, the concept of cell-mobility prediction is considered and we show how the analysis of user behavior, in terms of mobility, can be exploited to enhance QoS levels in current communications among mobile hosts and base stations (coverage cells, in general). This paper surveys different unconventional approaches and protocols, showing how it is possible to consider in-advance bandwidth reservations to achieve service continuity, avoiding call droppings during active sessions. First, we present the importance of in-advance reserving in wireless cellular networks, then we discuss the existing protocols and approaches for determining the most suitable future cells.

51 citations

Journal ArticleDOI
TL;DR: Experimental results show that FRA-JSCC outperforms the competing models in improving the video peak signal-to-noise ratio as well as in reducing the end- to-end delay.
Abstract: This paper investigates mobile video delivery in a heterogeneous wireless network from a video server to a multi-homed client. Joint source-channel coding (JSCC) has proven to be an effective solution for video transmission over bandwidth-limited, error-prone wireless networks. However, one major problem with the existing JSCC approaches is that they consider the network between the server and the client as a single transport link. The situation becomes more complicated in the context of multiple available links because involving a low-bandwidth, highly lossy, or long-delay wireless network in the transmission will only degrade the video quality. To address the critical problem, we propose a novel flow rate allocation-based JSCC (FRA-JSCC) approach that includes three key phases: (1) forward error correction redundancy estimation under loss requirement, (2) source rate adaption under delay constraint, and (3) dynamic rate allocation to minimize end-to-end video distortion. We present a mathematical formulation of JSCC to optimize video quality over multiple wireless channels and provide comprehensive analysis for channel distortion. We evaluate the performance of FRA-JSCC through emulations in Exata and compare it with the existing schemes. Experimental results show that FRA-JSCC outperforms the competing models in improving the video peak signal-to-noise ratio as well as in reducing the end-to-end delay.

50 citations

Journal ArticleDOI
TL;DR: A connection admission control (CAC) mechanism for IEEE 802.16 broadband wireless access Standard is introduced, based on bandwidth reservation concept, which provides higher priority to VoIP calls compared to other types of traffic in the network.
Abstract: In this letter we introduce a connection admission control (CAC) mechanism for IEEE 802.16 broadband wireless access Standard. Our scheme is based on bandwidth reservation concept and has been developed considering the problem of "busy hour" in communications traffic variation during a typical day. The proposed solution, which is compatible to the IEEE 802.16 Standard, provides higher priority to VoIP calls compared to other types of traffic in the network. The performance of the proposed scheme is evaluated by means of computer simulations, while an analytical solution is provided as well.

28 citations

Journal ArticleDOI
TL;DR: A ROBust BandwIdth Aggregation (ROBBIA) scheme that includes three phases: FEC redundancy adaption, transmission rate assignment, and path interleaving is proposed that outperforms existing bandwidth aggregation approaches in improving video quality in terms of PSNR.
Abstract: Bandwidth aggregation is the process of integrating the limited channel resources available in heterogeneous wireless networks. Optimizing this process is an important step towards improving the throughput and reliability for the bandwidth-demanding video applications. In this paper, we investigate the bandwidth aggregation for real-time video delivery in heterogeneous wireless networks from a video server to a multihomed client. Forward Error Correction (FEC) coding is commonly adopted for data protection in implementing loss-resilient wireless video transmission systems. However, the inherent channel unreliability, along with the video traffic variability, can significantly degrade the FEC performance. To address the critical issues, we propose a ROBust BandwIdth Aggregation (ROBBIA) scheme that includes three phases: (1) FEC redundancy adaption, (2) transmission rate assignment, and (3) path interleaving. We present a mathematical formulation of the transmission scheduling to minimize end-to-end video distortion and provide comprehensive analysis for the channel distortion. We conduct the performance evaluation in the Exata and simulation results show that ROBBIA outperforms existing bandwidth aggregation approaches in improving video quality in terms of PSNR (Peak Signal-to-Noise Ratio).

16 citations

Patent
02 Apr 2009
TL;DR: In this paper, the authors present methods for handling an emergency call along with its position location in the WiMAX network, and for performing a handover of the emergency call for a multi-mode mobile station that supports multiple wireless standards.
Abstract: Certain embodiments of the present disclosure relate to methods for handling an emergency call along with its position location in the WiMAX network, and for performing a handover of the emergency call for a multi-mode mobile station that supports multiple wireless standards.

13 citations