新型的无线接入技术—蓝牙

介绍蓝牙技术的发展历史和概念 ,重点讲述了蓝牙技术的系统组成及其技术特点 ,并对其未来的发展进行了展望。     

Ad hoc networking with Bluetooth: key metrics and distributed protocols for scatternet formation

Bluetooth is a promising technology for personal/local area wireless communications. A Bluetooth scatternet is composed of simple overlapping piconets, each with a low number of devices sharing the same radio channel. A scatternet may have different topological configurations, depending on the number of composing piconets, the role of the devices involved and the configuration of the links. This paper discusses the scatternet formation issue by analyzing topological characteristics of the scatternet formed. A matrix-based representation of the network topology is used to define metrics that are applied to evaluate the key cost parameters and the scatternet performance. Numerical examples are presented and discussed, highlighting the impact of metric selection on scatternet performance. Then, a distributed algorithm for scatternet topology optimization is introduced, that supports the formation of a “locally optimal” scatternet based on a selected metric. Numerical results obtained by adopting this distributed approach to “optimize” the network topology are shown to be close to the global optimum.     

An enhanced and energy efficient communication architecture for Bluetooth wireless PANs

Bluetooth is a radio technology for Wireless Personal Area Networking (WPAN) operating in the 2.4 GHz ISM frequency band, and allows devices to be connected into short-range ad hoc networks. The Bluetooth medium access control protocol is based on the Master/Slave paradigm wherein any communication between slave devices has to go through the Master. While this model provides for simplicity, it incurs a longer delay between any two slave devices due to far from optimal packet forwarding, the use of double the bandwidth, and also additional energy wastage at the Master. Moreover, if more than two devices want to communicate as a group, this can only be achieved by either multiple unicast transmissions or a piconet-wide broadcast, clearly resulting in inefficiency. In this paper, we propose a novel Dynamic Slot Assignment (DSA) scheme whereby the Master device dynamically assigns slots to Slaves so as to allow them to communicate directly with each other without any Master intervention. This proposed communication architecture also provides for Quality of Service (QoS) requests, admission control, and multi-device conversation by which a multicast-like communication is implemented within a piconet. Through extensive simulation, we observe that DSA drastically enhances Bluetooth performance in terms of delay and throughput, while significantly reducing power consumption at the master and the overall piconet.     

Design of power-controlled class1 Bluetooth CMOS power amplifier

In this paper, an RF power amplifier intended for class 1 Bluetooth application is designed using 0.35 µm CMOS technology. A layout-aware macromodel for the BSIM3v3 MOSFET transistor for RF applications including substrate effect is investigated and used in this design. The model is validated for a 0.35 μm CMOS process using a transistor with total width of 90 μm and 18 fingers and it shows excellent agreement with the f_t and S-parameter measurement data up to 6 GHz. The effects of pads and bond wires are also taken into consideration during the design process of the PA. After post-layout simulations, the amplifier delivers an output power of 19 dBm with 33.7% PAE under 3.3 V supply. This amplifier has a power control feature; its two stage circuit utilizes a cascode configuration in its first stage in order to use its bias pin as a power control input for the amplifier. Using this method, the power control range can be decreased down to 1.4 dBm which satisfies the Bluetooth standard. The chip is fabricated and is currently under testing.     

蓝牙服务发现协议(SDP)的实现

该文在介绍蓝牙服务发现协议的服务记录和协议数据单元的基础上,着重描述了蓝牙服务发现协议的实现方法、实现的流程及数据包的封装,并分析了蓝牙SDP的发展。     

A Secure Protocol for Bluetooth Piconets Using Elliptic Curve Cryptography

In this article, the authors shall propose a new method for the implementation of secure Bluetooth piconets. Two requirements for the systems must be considered, i.e., privacy and authentication. Privacy ensures that an eavesdropper cannot intercept conversations between two slaves in piconets. Authentication ensures that service is not obtained fraudulently in order to avoid charge for usage. Additionally, a new key distribution scheme is designed for practical implementation in low-cost and low-power Bluetooth piconets. The proposed method employs elliptic curve cryptography for the use in the Bluetooth network. We have proper solutions to Bluetooth devices registration and Bluetooth piconets establishment. Furthermore, compared with Seo and Lee’s protocol, the proposed scheme has a lower computation cost.This research was partially supported by the National Science Council, Taiwan, R.O.C., under contract no.: NSC91-2213-E-324-003.     

BlueMesh: Degree-Constrained Multi-Hop Scatternet Formation for Bluetooth Networks

In this paper we describe BlueMesh, a new protocol for the establishment of scatternets, i.e., multi-hop wireless networks of Bluetooth devices. BlueMesh defines rules for device discovery, piconet formation and piconet interconnection so to generate connected scatternets with the following desirable properties. BlueMesh forms scatternets without requiring the Bluetooth devices to be all in each other transmission range. BlueMesh scatternet topologies are meshes with multiple paths between any pair of nodes. BlueMesh piconets are made up of no more than 7 slaves. Simulation results in networks with over 200 nodes show that BlueMesh is effective in quickly generating a connected scatternet in which each node, on average, does not assume more than 2.4 roles. Moreover, the route length between any two nodes in the network is comparable to that of the shortest paths between the nodes.     

蓝牙认证V5.2和V5.1版解析

介绍了蓝牙认证中V5.2、V5.1版本在功能、协议层及射频一致性等方面的主要差异及认证流程、测试流程、注意事项等,企业可根据自己的产品选择合适的蓝牙认证标准。     

基于太阳能的智能庭院灯设计与实现

针对家庭院子里庭院灯布线不便和功能需求问题,设计并实现了一种基于太阳能电池板供能的智能庭院灯系统。对于普通庭院灯进行了功能上的改进,提升用户体验。采用STM32F103单片机作为主控芯片,根据人体热释电和光感传感器采集信息进行智能控制,并通过温湿度、雨水检测等传感器采集数据,使用蓝牙发送到上位机。测试结果表明,系统运行稳定,功耗较低,可满足实际生活需求。     

基于模糊逻辑与数据融合的智能导盲手杖

在分析国内外现有导盲设备的基础上,引入模糊逻辑与数据融合算法,对传统超声波探测方式进行改进。自行设计并组建超声波障碍物探测网络,进行数据采集、融合与分析,实现了对障碍物方位与距离的综合探测。此外,利用GPS模组、网络通信技术以及语音合成芯片设计,并实现了智能导盲手杖的GPS位置信息实时获取、GPRS短信提示、蓝牙语音提示等功能,以满足盲人日常生活的需求。