The Experts below are selected from a list of 324 Experts worldwide ranked by ideXlab platform

Saewoong Bahk - One of the best experts on this subject based on the ideXlab platform.

  • adaptable adaptive control of data rate transmission power and connection interval in Bluetooth low energy
    Computer Networks, 2020
    Co-Authors: Eunjeong Park, Myungsup Lee, Hyungsin Kim, Saewoong Bahk
    Abstract:

    Abstract This work investigates run-time parameter control for Bluetooth Low Energy (BLE), based on the latest Bluetooth Specification 5 released in 2016. Compared to the previous version, Bluetooth Specification 5 provides more options for data rate and transmission power and gives room for adaptive parameter control to improve BLE performance in time-varying wireless environments. To the best of our knowledge, this work is the first systematic study of this regime in the research community. We experimentally study how more parameter options in Bluetooth Specification 5 impact BLE performance. Based on the preliminary study, we design A d a p t a B L E that dynamically adjusts connection interval, data rate, and transmission power together to satisfy quality of service (QoS) requirements without wasting energy. Through extensive performance evaluation on off-the-shelf BLE chips, we show that A d a p t a B L E provides stable performance regardless of wireless environments and reduces QoS failures by 5 times with similar energy consumption compared to the state-of-the-art parameter control scheme for BLE.

  • MobiSys - Data Rate and Transmission Power Adaptation for Bluetooth Low Energy (poster)
    Proceedings of the 17th Annual International Conference on Mobile Systems Applications and Services, 2019
    Co-Authors: Eunjeong Park, Myungsup Lee, Saewoong Bahk
    Abstract:

    The use of Bluetooth Low Energy (BLE) has steadily increased since 2010. Bluetooth Specification 4.2 defined only one data rate, 1 Mb/s. However, Bluetooth Specification 5 released in 2016 specifies 2 Mb/s and coded PHY for higher throughput and for more stable transmission, respectively. In addition, this version of Specification defines transmission power from -20 dBm to 20 dBm. In this paper, we propose AdaptaBLE, an algorithm that selects the data rate and transmission power of BLE by considering link stability and energy consumption. We implement AdaptaBLE on real devices and measure its performance. As a result, we confirm that AdaptaBLE successfully lowers energy consumption while keeping the link stable.

Enrico Gregori - One of the best experts on this subject based on the ideXlab platform.

  • Bluetooth: Architecture, Protocols and Scheduling Algorithms
    Cluster Computing, 2002
    Co-Authors: Raffaele Bruno, Marco Conti, Enrico Gregori
    Abstract:

    The paper focuses on one of the emerging technologies for constructing a Mobile ad hoc network: Bluetooth. Bluetooth can be exploited on small scales, to build ad hoc wireless Personal Area Networks (WPAN), i.e., networks that connect devices placed inside a circle with radius of 10 m. The Bluetooth technology is just starting to appear on the market and its architecture and protocols are not widely known. For this reason, the first part of the paper contains a tutorial-oriented description of the Bluetooth architecture and protocols. In addition, in the paper we extensively discuss the performance of this technology by investigating, through simulation, the main performance figures: the protocol efficiency (channel utilization), the response time, and the system power (i.e., the ratio between throughput and delay). Specifically, the performance analysis focuses on the algorithms for scheduling the transmissions in a Bluetooth network. The Bluetooth Specification indicates a Round Robin scheduler as possible solution, that is each slaves is polled in a consecutive order. For this reason, we first study in depth the performance figures of a Bluetooth network with a Round Robin scheduler. Our results point out the inefficient Bluetooth behavior under asymmetric traffic conditions. To solve this problem we propose and analyze an innovative scheduling algorithm specifically tailored to the Bluetooth characteristic. This algorithm, named efficient double-cycle (EDC), dynamically adapts the polling frequency to the traffic conditions. A performance study indicates that our EDC scheduler always outperforms the Round Robin scheduler.

C. Scholz - One of the best experts on this subject based on the ideXlab platform.

  • LCN - Adaptive scatternet support for Bluetooth using sniff mode
    Proceedings LCN 2001. 26th Annual IEEE Conference on Local Computer Networks, 1
    Co-Authors: S. Baatz, M. Frank, C. Kuhl, Peter Martini, C. Scholz
    Abstract:

    Future applications of Bluetooth are likely to include ad-hoc networking. Therefore, it is desirable to interconnect multiple Bluetooth piconets to form a scatternet. Up to now, there is no extensive proposal for scatternet support available. We present and analyze an adaptive scheme for scatternet scheduling that is based on the sniff mode and thus does not require substantial modification of the current Bluetooth Specification. The suitability of our approach is shown by first simulation results.

  • INFOCOM - Bluetooth scatternets: an enhanced adaptive scheduling scheme
    Proceedings.Twenty-First Annual Joint Conference of the IEEE Computer and Communications Societies, 1
    Co-Authors: S. Baatz, M. Frank, C. Kuhl, Peter Martini, C. Scholz
    Abstract:

    The vision of ad-hoc networking with Bluetooth includes the concept of devices participating in multiple "piconets" and thereby forming a "scatternet". However, the details of scatternet support for Bluetooth are not specified yet. This paper presents a scheme for Bluetooth scatternet operation that adapts to varying traffic patterns. Being based on sniff mode, it does not require substantial modification of the current Bluetooth Specification and may thus be incorporated into currently available Bluetooth products. We present simulation results that confirm the applicability of our approach to realistic scenarios.

Vojislav B. Misic - One of the best experts on this subject based on the ideXlab platform.

  • Impact of Bluetooth MAC layer on the performance of TCP traffic
    Wireless Communications and Mobile Computing, 2006
    Co-Authors: Jelena Misic, Kalok Chan, Vojislav B. Misic
    Abstract:

    Recent updates of the Bluetooth Specification have introduced significant changes in the Bluetooth protocol stack, including optional flow control. When the Bluetooth piconet is used to carry TCP traffic, complex interactions between TCP congestion control mechanisms and data link layer controls of Bluetooth will occur. In this paper, we model the performance of the piconet with TCP traffic, expressed through segment loss probability, round-trip time, and goodput, through both probabilistic analysis and discrete-event simulations. We show that satisfactory performance for TCP traffic may be obtained through proper dimensioning of the Bluetooth architecture parameters. Copyright © 2006 John Wiley & Sons, Ltd.

  • WCNC - TCP traffic in Bluetooth 1.2: performance and dimensioning of flow control
    IEEE Wireless Communications and Networking Conference 2005, 1
    Co-Authors: Jelena Misic, Kalok Chan, Vojislav B. Misic
    Abstract:

    Recent updates of the Bluetooth Specification to version 1.2 have introduced significant changes in the Bluetooth protocol stack, including optional flow control. When the Bluetooth piconet is used to carry TCP traffic, complex interactions between TCP congestion control mechanisms and Bluetooth data link layer controls will occur. In this paper, we analyze the performance of the piconet with TCP traffic, and show that satisfactory performance for TCP traffic may be obtained through proper dimensioning of the Bluetooth architecture parameters.

  • GLOBECOM - Improving the performance of Bluetooth piconets with synchronous and asynchronous traffic
    GLOBECOM '03. IEEE Global Telecommunications Conference (IEEE Cat. No.03CH37489), 1
    Co-Authors: Vojislav B. Misic, Jelena Misic, Kalok Chan
    Abstract:

    The Bluetooth Specification allows both asynchronous (ACL) and synchronous (SCO) links to be present in a piconet. However, the performance of ACL traffic rapidly deteriorates when an SCO link is present. This paper investigates the possibility of replacing the Bluetooth SCO connection with a QoS-constrained asynchronous link that uses multi-slot ACL packets. We have analyzed the performance of this scheme, dubbed pseudo-SCO, under limited service and exhaustive service scheduling. It was found that the pseudo-SCO scheme allows asynchronous traffic to experience lower delays than with the regular SCO connection, while supporting the bandwidth requirements of SCO traffic.

Shu-ming Hsu - One of the best experts on this subject based on the ideXlab platform.

  • WCNC - A novel hold-mode-based adaptive inter-piconet scheduling algorithm in Bluetooth scatternets
    IEEE Wireless Communications and Networking Conference 2006. WCNC 2006., 2006
    Co-Authors: Ching-fang Hsu, Shu-ming Hsu
    Abstract:

    In this paper, we proposed a new inter-piconet scheduling algorithm based on HOLD mode, a power saving mode of Bluetooth, to reduce the average delay of inter-piconet packets and maximize the utilization of the bridge as possible. The delay of inter-piconet traffic is incurred by the phenomenon that a bridge stays in a piconet which has no inter-piconet traffic to be processed while inter-piconet packets of other piconets have to wait in queues. Consequently, our proposed scheme aims at determining the time duration which the bridge should spend in different piconet according to the traffic pattern so that the idle time of a bridge can be minimized. In addition, our design completely follows Bluetooth Specification, i.e., there is no need to modify the Specification or add any other device. So it is easy to implement and integrate the proposed scheduling algorithm into Bluetooth Specification. Finally, we show the superiority of the proposed scheme on average delay, throughput, and scalability by simulation