An efficient algorithm for scheduling in bluetooth piconets and scatternets

Bluetooth is a short-range radio technology operating in the unlicensed industrial-scientific-medical (ISM) band at 2.45 GHz. A piconet is basically a collection of slaves controlled by a master. A scatternet, on the other hand, is established by linking several piconets together in an ad hoc fashion to yield a global wireless ad hoc network. This paper proposes a scheduling policy that aims to achieve increased system throughput and reduced packet delays while providing reasonably good fairness among all traffic flows in bluetooth piconets and scatternets. We propose a novel algorithm for scheduling slots to slaves for both piconets and scatternets using multi-layered parameterized policies. Our scheduling scheme works with real data and obtains an optimal feedback policy within prescribed parameterized classes of these by using an efficient two-timescale simultaneous perturbation stochastic approximation (SPSA) algorithm. We show the convergence of our algorithm to an optimal multi-layered policy. We also propose novel polling schemes for intra- and inter-piconet scheduling that are seen to perform well. We present an extensive set of simulation results and performance comparisons with existing scheduling algorithms. Our results indicate that our proposed scheduling algorithm performs better overall on a wide range of experiments over the existing algorithms for both piconets (Das et al. in INFOCOM, pp. 591–600, 2001; Lapeyrie and Turletti in INFOCOM conference proceedings, San Francisco, US, 2003; Shreedhar and Varghese in SIGCOMM, pp. 231–242, 1995) and scatternets (Har-Shai et al. in OPNETWORK, 2002; Saha and Matsumot in AICT/ICIW, 2006; Tan and Guttag in The 27th annual IEEE conference on local computer networks(LCN). Tampa, 2002). Our studies also confirm that our proposed scheme achieves a high throughput and low packet delays with reasonable fairness among all the connections.     

Load-adaptive inter-piconet scheduling in small-scale Bluetooth scatternets

Bluetooth enables wireless communication via ad hoc networks. The basic topology (piconet) is a collection of slaves controlled by a master. A scatternet is a multihop network of piconets. We anticipate that most scatternets will be composed of only a few piconets. However, even in small scatternets, efficient data flow requires the design of inter-piconet scheduling algorithms. Thus, this article presents and evaluates a load adaptive scheduling algorithm tailored for small-scale scatternets. The main advantage of this algorithm is the use of the Bluetooth low-power hold mode, which allows greater flexibility than other low-power modes. A simulation model has been developed in order to evaluate the performance of the algorithm. We show that the results obtained by the model are very close to the analytic results. Then we evaluate the performance of various intra-piconet scheduling algorithms. Finally, we present simulation results regarding inter-piconet scheduling, and compare the proposed algorithm to algorithms using the sniff mode.     

Dynamic traffic-aware routing algorithm for multi-sink wireless sensor networks

In this paper, a distributed traffic-balancing routing algorithm is proposed for multi-sink wireless sensor networks that effectively distributes traffic from sources to sinks. Each node has a gradient field that is used to decide on a neighbor node to reach a sink. The node’s gradient index contains (1) the distance cost from a source to a respective sink, and (2) traffic information from neighboring nodes. The proposed algorithm considers the traffic being faced by surrounding neighbors before forwarding packets to any sink using gradient search for routing and providing a balance between optimal paths and possible congestion on routes toward those sinks. The key objective of this work is to achieve traffic-balancing by detecting congested areas along the route and distributing packets along paths that have idle and underloaded nodes. Extensive simulations conducted to evaluate the performance of the proposed scheme indicate that it effectively reduces the overall packet delay, energy consumption and improves the packet delivery ratio under heavy traffic.     

A CMOS bandpass filter for low-IF bluetooth receivers

A CMOS fully integrated 12th-order bandpass filter for low interemdiate frequency Bluetooth receivers is presented. The design is optimized to meet the selectivity and dynamic range requirements of Bluetooth while consuming relatively low power. The filter is based on unity gain cells and utilizes linearized MOSFET resistors for tuning. It exhibits a bandwidth of 1 MHz and a programmable center frequency range of 2 to 4 MHz. Experimental results obtained from a standard 0.5-/spl mu/m CMOS chip show that the filter exhibits an in-band dynamic range of 53.3 dB at gain of 0 dB, and 52 dB at gain of 15 dB, while consuming a total current of 1.32 mA. Attenuations of more than 10, 38, and 55 dB, are achieved for blockers one, two, and three, respectively.     

CLIP antenna for wireless bluetooth applications

In this paper, a novel design for a coplanar waveguide antenna is developed that consists of two U-shaped slots. The antenna is named CLIP. The antenna was designed for a central frequency of 2.4 GHz, with an input impedance of 50 /spl Omega/. The antenna dimensions represent a 72% size reduction compared to a conventional microstrip rectangular-patch antenna. The measured antenna bandwidth was about 11%, while its gain was about 17 dB. These values are fairly acceptable in all wireless communication systems. The antenna configuration has a bidirectional radiation pattern, while a unidirectional radiation pattern was achieved by using a /spl lambda//sub 0//4 reflector with a metal plate. A 2/spl times/2 multi-element sub array was implemented to widen the application area. The mutual coupling between adjacent elements was low. Orthogonal-plane coupling between adjacent elements was introduced to increase the reduction in the mutual coupling. The mutual coupling level was reduced to less than -23 dB in all coupling planes. The CLIP antenna element and arrays were fabricated. Experimental measurements showed very good performance, which agreed well with simulation results.     

Bluetooth scatternets: criteria, models and classification

Bluetooth ad hoc networks are constrained by a master/slave configuration, in which one device is the master and controls the communication with the slave devices. The master and up to seven active slave devices can form a small Bluetooth network called a piconet. In order to build larger network topologies, called scatternets, the piconets must be interconnected. Scatternets are formed by allowing certain piconet members to participate in several piconets by periodically switching between them. Due to the fact that there is no scatternet formation procedure in the Bluetooth specification, numerous different approaches have been proposed. We discuss criteria for different types of scatternets and establish general models of scatternet topologies. Then we review the state-of-the-art approaches with respect to Bluetooth scatternet formation and compare and contrast them.     

Efficient packetisation scheme for bluetooth video transmission

The Bluetooth wireless link is likely to be the last hop in the delivery of an encoded streamed video clip. It is shown that it is preferable to optimally map arriving IP packets onto Bluetooth packets than to preserve the stream's internal synchronisation structure. Video quality improves and latency reduces, even when there is cross traffic on the piconet     

Distributed self-healing and variable topology optimization algorithms for QoS provisioning in scatternets

Bluetooth is an enabling technology for Personal Area Networks. A scatternet is an ad hoc network created by interconnecting several Bluetooth piconets, each with at most eight devices. Each piconet uses a different radio channel constituted by a frequency hopping code. The way the devices are grouped in different piconets and the way the piconets are interconnected greatly affect the performance of the scatternet in terms of capacity, data transfer delay, and energy consumption. There is a need to develop distributed scatternet formation algorithms, which guarantee full connectivity of the devices, reconfigure the network due to mobility and failure of devices, and interconnect them such a way to create an optimal topology to achieve gainful performance. The contribution of this paper is to provide an integrated approach for scatternet formation and quality-of-service support (called SHAPER-OPT). To this aim, two main procedures are proposed. First, a new scatternet formation algorithm called self-healing algorithm producing multihop Bluetooth scatternets (SHAPER) is developed which forms tree-shaped scatternets. A procedure that produces a meshed topology applying a distributed scatternet optimization algorithm (DSOA) on the network built by SHAPER is then defined. Performance evaluation of the proposed algorithms, and of the accordingly created scatternets, is carried out by using ns2 simulation. Devices are shown to be able to join or leave the scatternet at any time, without compromising the long term connectivity. Delay for network setup and reconfiguration in dynamic environments is shown to be within acceptable bounds. DSOA is also shown to be easy to implement and to improve the overall network performance.     

BLE蓝牙通信卡蓝牙功能的技术研究与测试

2021年5G开启大规模商用,数字货币、数字身份识别等行业在5G网络环境下加速推广[1].在手机通信卡上加载数字货币、数字身份识别等行业应用时,存在部分Android终端和苹果终端无法通过ISO/IEC 7816机卡通道访问手机通信卡的问题,导致数字货币、数字身份识别等行业应用无法在此类终端上使用.为提升数字货币、数字...     

功能强大的蓝牙无线技术

1.0 蓝牙无线技术与个人无线连接 据从事市场调研的Strategies Unlimited公司分析,作为体积小、成本低,以及在移动语音通信和计算设备之间的短程射频链接规范,蓝牙技术有望在2004年创造一个价值5亿美元的芯片市场。 目前已并入科胜讯系统公司无线通信业务部的Philsar半导体公司根据个人无线连接(PWC)理念定义蓝牙市场。PWC是一种无线概念,允许网络直观地基于终端用户,并通过无线通信提供无与伦比的个人连接。     

QoTa-MPR: QoS-oriented and traffic-aware multi-path routing protocol for internet of remote things

Telecommunication Systems - Internet of Remote Things (IoRT) is widely used in both military and civilian applications. However, due to the unique characteristics, which is characterized as...     

A statistical framework for EDF scheduling

Earliest deadline first (EDF) has become one of the most promising scheduling schemes for providing quality-of-service differentiation over high speed networks. In this letter, we study the deadline violation (loss) probability at an EDF scheduling switch. An analytical framework has been developed for estimating the loss probabilities for the aggregated traffic and the individual flows. This enables us to determine whether a given flow can meet its deadline with the required loss probability. As illustrated from the simulation results using real network traffic, the asymptotic approximations presented are accurate enough to predict the real metrics.     

设计RF CMOS蓝牙收发器

使用CMOS RFIC设计2.4GHz蓝牙收发器需要在设计过程中的所有阶段对关键性能进行仔细的验证。这可以通过EDA软件的几个功能来实现,如提供晶片厂模型库,带有蓝牙测试信号的系统兼容性测试模板,还可以和测试仪器的链接,验证仿真数据和实际测量结果是否一致。     

A new CMOS channel select filter for dual mode bluetooth/WLAN direct-conversion receiver

Design of a CMOS 4th-order channel select filter for integrated dual mode Bluetooth/WLAN direct-conversion receiver is presented. The bandwidth of the filter can be programmed from 200 kHz to 8 MHz to accommodate both standards. The proposed filter provides low power, and small area design solution. Post-layout simulation results show that the filter satisfies the selectivity and dynamic range requirements of both applications while consuming total standby power of 1.88 mW.     

Adaptive frequency hopping for bluetooth robust to WLAN interference

In this letter, we propose a new adaptive frequency hopping (AFH) scheme for Bluetooth to mitigate interference from IEEE 802.11x based wireless local area network (WLAN). To fast classify available channels for the Bluetooth, we first group the Bluetooth channels according to the channel allocation of WLAN and classify groups instead of Bluetooth channels. Then, we employ a moving average technique to estimate the status of Bluetooth channels in groups more accurately. The performance of the proposed scheme is verified by computer simulation. Simulation results show that the proposed AFH scheme significantly outperforms conventional schemes.     

Optimal communication in bluetooth piconets

Bluetooth is a low-power, low-cost, short-range wireless communication system operating in the 2.4-GHz industrial, scientific, and medical (ISM) band. Bluetooth links use frequency hopping whereby each packet is sent on a single frequency while different packets are sent on different frequencies. Further, there are a limited number of packet sizes. We show that we can exert indirect control over transmission conditions by choosing the packet size transmitted over each frequency as a function of the channel conditions. Our goal then is to provide a packet-size-selection algorithm that can maximize the throughput in a Bluetooth piconet in the presence of lossy wireless channels. We first develop a renewal-theory-based mathematical model of packet transmission in a frequency-hopping system such as a Bluetooth piconet. We use this model to show that a threshold-based algorithm for choosing the packet lengths maximizes the throughput of the system. We provide an algorithm that determines the optimal thresholds efficiently. We show the optimality of this algorithm without using standard optimization techniques, since it is not clear that these techniques would be applicable given the functions involved. Using simulations, we observe that this strategy leads to significantly better throughput as compared to other baseline strategies, even if the assumptions made to prove optimality are relaxed.     

A scheduling heuristic for maximizing wirebonder throughput

Process planning and scheduling is an important part of managing the complex dynamic back end (i.e., test, assembly, and packaging) of the semiconductor manufacturing process. One of the most critical toolsets in the back end in terms of manufacturing capacity and product flow is the wirebonders that electrically connect bare silicon die to lead frames via thin metal wires. We develop two approaches for maximizing throughput on a group of wirebonders containing three different wirebonder types. Although our mathematical programming approach is capable of producing a near-optimal wirebonder schedule for any production day of interest, the computational requirements of this approach are unacceptable for implementation in a real-world back-end facility. Therefore, we develop a rule-based heuristic approach for wirebonder scheduling capable of producing high-quality schedules in a much shorter period of time.     

A scheduling application for WDM optical networks

Optical networking using WDM technology has matured considerably, and commercial WDM network equipment and WDM network control and management prototypes have appeared. To use such a network efficiently, a scheduling facility and its enabling mechanisms have to be provided. This scheduling facility should be integrated to interoperate with the rest of the network control and management software such as connection manager or signaling daemon. We present a scheduling application to address this need. The architecture for the application and its key components are presented. Agent-related enabling mechanisms are introduced to monitor the optical signal quality and collect performance measurements. A resource broker is used to manage the communication and interoperability between agents and the application. An event service is developed to decouple the communication between the agents and the scheduling application, and to enable the communication among the agents themselves. The scheduling application consists of the quality of signal information and threshold objects, current network usage, history data module, scheduling module, and access to a performance database. To provide traffic control and high network resource utilization, the application is equipped with wavelength scheduling algorithms. An experimental study for the basic scheduling algorithms has been conducted over the MONET DC network.     

A distributed scheduling for agro-food manufacturing problems

Workshop scheduling problems can be considered as one of the main factors to improve the productivity and efficiency of a manufacturing system. The continuous evolution and the dynamic characteristics of industrial workshops, particularly those of agro-food industries, impose the generation of a real time decision scheduling process. In the agro-food industries, the products to be processed and the used primary products are characterized by their limit validity dates which generate some particularly and especially antagonist criteria. A distributed decision support system for real time scheduling is described in this paper. It is based on an original cooperative approach aimed to elaborate robust decisions that propose to the "best action" to the decision maker. The decision process is distributed all along the production chain. At each decision time, in order to ensure coherency, we have to take into account the neighborhood constraints in order to simultaneously satisfy different criteria which do not have the same importance. An aggregation criteria system is defined to manage the criteria among their importance degrees. We define a decisional model based on the evaluation and the comparison of a set of proposed actions.