蓝牙系统定时和收发处理的实现

蓝牙(Bluetooth)是一种短距离低功耗无线技术，它提供低成本、近距离的无线通信，构成固定与移动设备通信环境中的个人网络，取代现有的PC、打印机、传真机和移动电话等设备上的有线接口，使得近距离内各种信息设备能够实现无缝资源共享。蓝牙系统的定时和收发处理是无线局域网的基础。它直接面对个人和商务的无线连接应用，为已存在的数字网络和外设提供通用接口(GB)以组建一个远离固定网络的个人特别连接设备群，即个人局域网PAN(Personal Area Network)。在既有的有线网路的基础上，完成网络无线化的构建。     

基于Bluetooth技术的个人多媒体无线网络系统应用研究

Bluetooth技术能在短距离内用无线接口代替有线电缆连接,实现个人多媒体无线网络系统.本文介绍了Bluetooth技术的基本特性,讨论了基于Bluetooth技术的多媒体无线网络系统(PMWNS)的结构和通信协议软件栈,并对PMWNS的主/从单元连接建立和多PMWNS的从单元资源共享等问题进行了研究.     

一种基于Bluetooth的路由技术

Bluetooth是一种用于短距离无线通信的新技术,该文首先描述Bluetooth通信技术中Piconet网络和Scatternet网络的特征,并针对这些特征,分析了路由方法设计的基本原则,然后提出了一种IPover Bluetooth的路由方法,重点分析了在Piconet中,Scatternet中、跨Scatternet几种情况下的路由发现和数据传递的方法,并提出Bluetooth单元的跨Scatternet漫游方法。     

蓝牙网络封装协议

介绍了蓝牙网络封装协议（BNEP：Bluetooth Network Encapsulation Protocol）的定义、格式及所具有的对上层IP协议提供类型似于以太网的接口和支持IEEE 802.3/Ethernet封装的网络协议等功能。由于BNEP能把IEEE802.3/Ethernet封装支持的网络协议包封装起来，直接通过蓝牙L2CAP协议进行无线传输，因此介绍了一种BNEP在蓝牙个人无线局域网（PAN：Personal Area Network）中，通过一个网络接入点来访问远程网络的应用。     

基于蓝牙以太封装技术的无线个域网

蓝牙以太封装技术(BEE)用于实现网络层到蓝牙设备L2CAP层的协议映射,它为蓝牙个域网(PAN)的实现提供新的解决方案。文章将详细讨论BEE的实现以及如何在BEE的基础上,构建网络接入点和组建蓝牙PAN,并以实际测试的统计数据,说明BEE的优越性。     

蓝牙技术应用与中国的发展机遇

蓝芽(Bluetooth)作为一种新的短距离无线通信技术标准,正在受到通信业界的广泛关注,已经成为当前人们讨论的一个热门话题.以中世纪北欧海盗国王哈拉德·布鲁图斯(Halad Bluetooth)名字命名的这项蓝芽技术,最近已被权威性杂志<网络计算>评为"十年来十大热门新技术产品"之一.     

红外与蓝牙技术的比较

近年来，随着各种短距离无线通信技术的发展，学术界提出了一个新的概念：个人局域网(Personal Area Network, PAN)。PAN的核心思想是，用无线电或红外线代替传统的有线电缆，实现个人信息终端的智能化互联，组建个人化的信息网络。从计算机网络的角度来看，PAN是一个局域网；从电信网络的角度来看，PAN是一个接入网，因此有人把PAN称为电信网络“最后一米”的解决方案。PAN定位在家庭与小型办公室的应用场合。其主要应用范围包括：话音通信网关、数据通信网关、信息电器互联与信息自动交换等。四种PAN技术PAN的实现技术主要有：…     

蓝牙技术简介

蓝牙(Bluetooth)是一种低功率短距离的无线连接技术标准的代称，“蓝牙”一词取自一位在公元10世纪统一了丹麦的国王，哈拉德二世(Harald)的绰号，即蓝牙(Bluetooth)。     

电子产品的蓝牙功能设计博采众长

蓝牙(Bluetooth)技术是一种短距离无线网络连接技术。具有蓝牙功能的电子产品可以非常容易地在一个小范围内,组成一个临时的专用网络(微微网,Picnet),并使这些产品通过此网络方便地建立一种际准的无线电连接,以取代有线电缆连接,来进行数据的传送。     

蓝牙技术联盟发布mesh标准将提供多点互联的工业级解决方案

近日,蓝牙技术联盟(Bluetooth Special Interest Group,简称SIG)正式宣布蓝牙(Bluetooth)技术全面支持mesh网状网络.全新的mesh功能支持多对多设备传输,并特别提高构建大范围网络覆盖的通信效能,适用于楼宇自动化、无线传感器网络等需要数以万计的设备在可靠、安全的环境下传输的物联网解决方案. 蓝牙mesh网络是用于建立多对多设备通信的低功耗蓝牙(Bluetooth Low Energy,也称为BluetoothLE)新的网络拓扑,允许创建基于多个设备的大型网络,网络可以包含数十、数百甚至数千台蓝牙mesh设备,这些设备之间可以相互进行信息的传递,可以为楼宇自动化、无线传感器网络、资产跟踪和其他解决方案提供理想的选择.     

基于蓝牙的个人局域网(PAN)的设计

通信技术迅速发展,为了更好地满足所有移动计算机和通讯设备的通讯需要,蓝牙特别兴趣小组(SIG)提出了一个新的概念———蓝牙个人区域网(Personal Area Networking)。分析了蓝牙个人区域网(PAN)的原理,同时提出基于蓝牙模块的蓝牙个人区域网的设计方案(包括协议的实现,数据的转发,模块的选择,整体的设计等)。     

Personal Area Networks: Bluetooth or IEEE 802.11?

Interconnecting all our electronic devices we carry around, such as cellular phones, PDAs, and laptops, with wireless links requires a cheap, low-power radio technology that still delivers good performance. In this context, the Bluetooth wireless technology was developed to meet the requirements introduced by these personal area networks (PANs). However, today we see a widespread deployment of wireless local area network (WLAN) radios (primarily IEEE 802.11b) also in small devices, such as PDAs. This paper will compare the PAN capabilities of a Bluetooth-based system with an IEEE 802.11b-based system. In order to focus the comparison on link and networking functionality, the IEEE 802.11b radio is assumed to be operating at the same power level as the Bluetooth radio (i.e., assuming a 0 dBm radio). Results are obtained by means of simulations in which throughput and delay are measured for multihop and overlaid PANs. Estimations on power usage are also given in the simulations. The results indicate that as the number of PANs increases, the Bluetooth-based PANs basically maintain the same bandwidth per PAN, while the corresponding IEEE 802.11-based PANs suffer significantly from the increased co-channel interference. However, for cases with a few co-channel-interfering PANs (2-3 PANs hosting about 10-15 nodes), the IEEE 802.11b-based PANs offer a higher bandwidth per user than the corresponding Bluetooth PANs, which corresponds to the difference in link bandwidth between the two systems. At high interference levels, the Bluetooth PAN offers a higher capacity than the IEEE 802.11 PAN. The latter also shows unfairness among TCP connections in the PAN at high loads. The energy efficiency, defined as successfully transmitted bits per energy unit, decreases sharply for IEEE 802.11 with increased number of PANs, while Bluetooth maintains a constant level. Packet delays are also shown to be more stable for the Bluetooth PAN than for the IEEE 802.11 PAN as the number of PANs increases.     

An Analytical Study of the Delay in Bluetooth Networks Using the Personal Area Network Profile

Bluetooth is the most employed technology to develop wireless personal area networks. This letter studies the performance of Bluetooth transmissions that make use of the PAN (personal area network) profile. In particular, the study offers an analytical model that defines the optimal bound for the end-to-end data delay. The proposed 'delay budget' takes into account the overhead and segmentation provoked by the protocols involved in the transmission of user data. The model is empirically validated by comparing its results with those obtained through the measurements of actual Bluetooth connections.     

Analyzing the Secure Simple Pairing in Bluetooth v4.0

This paper analyzes the security of Bluetooth v4.0’s Secure Simple Pairing (SSP) protocol, for both the Bluetooth Basic Rate/Enhanced Data Rate (BR/EDR) and Bluetooth Low Energy (LE) operational modes. Bluetooth v4.0 is the latest version of a wireless communication standard for low-speed and low-range data transfer among devices in a human’s PAN. It allows increased network mobility among devices such as headsets, PDAs, wireless keyboards and mice. A pairing process is initiated when two devices desire to communicate, and this pairing needs to correctly authenticate devices so that a secret link key is established for secure communication. What is interesting is that device authentication relies on humans to communicate verification information between devices via a human-aided out-of-band channel. Bluetooth v4.0’s SSP protocol is designed to offer security against passive eavesdropping and man-in-the-middle (MitM) attacks. We conduct the first known detailed analysis of SSP for all its MitM-secure models. We highlight some issues related to exchange of public keys and use of the passkey in its models and discuss how to treat them properly.     

Future Applications of Bluetooth

Bluetooth is a short-range radio technology that is increasingly being provided in the various electronic devices that we carry around, such as laptops, mobile telephones and cameras. Bluetooth's supporters claim that it can deliver 'unprecedented productivity' through the seamless interconnection of these devices into a personal area network (PAN) — but does the technology really live up to this expectation? This paper investigates the claims surrounding Bluetooth, and compares its capabilities and potential applications with the existing technologies of DECT and wireless LAN. Bluetooth usage scenarios are considered in the areas of ad hoc networks, the home, the office environment, mCommerce and public access wireless hot-spots. Widespread implementation in devices does not mean widespread usage, and barriers to easy operation are examined to see if Bluetooth can move beyond its personal area network role into new areas of networking that could benefit a broad range of users.     

Overhead and Segmentation Mismatch Effect on Bluetooth WPAN Performance

Currently, Bluetooth is the most widely used technology for Wireless Personal Area Networks (WPAN). Quality-of-Service (QoS) support is critical to ensure bandwidth maximization for mobile applications based on this WPAN technology. The overhead introduced by the different layers of Bluetooth protocol may have a serious impact on WPAN performance. However, most studies of Bluetooth performance neglect this overhead and assume that data are directly transmitted over L2CAP (Logical Link Control and Adaptation Protocol) or even HCI (Host Controller Interface) layers. In fact, this option is not feasible in most Bluetooth applications, as they integrate actual devices that implement a particular Bluetooth profile, usually SPP (Serial Port Profile). The use of profiles cannot be disregarded as they guarantee the interoperability between devices from different vendors. The aim of this paper is to characterise the performance of a Bluetooth WPAN (specifically the end-to-end delay and the throughput) when profiles are utilised. This study takes into account the overhead added by the protocols taking part in the transmission of user data. This paper also explores the effect of segmentation mismatch that may appear when the maximum size for data in each layer of the architecture is different. The analysis has been focused on SPP and PAN (Personal Area Networks) profiles. In the case of the PAN profile, the study concludes that the network performance decreases for user data sizes greater than 1,472 bytes, since the excessive overhead added by the network layer is increased by the IP (Internet Protocol) fragmentation. In the case of SPP, an inappropriate choice of the maximum data unit at RFCOMM (Radio Frequency Communication for Serial Cable Emulation Protocol based on ETSI TS 07.10) and L2CAP layers can also heavily affect the transmission delay.

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.     

BlueStar: Enabling Efficient Integration Between Bluetooth WPANs and IEEE 802.11 WLANs

Bluetooth is a radio technology for Wireless Personal Area Networking (WPAN) operating in the 2.4 GHz ISM frequency band. So far, there has been little research on how Bluetooth-enabled devices can effectively and efficiently have uninterrupted access to wide area networks (WAN) such as the Internet. We introduce a novel architecture (BlueStar) whereby selected Bluetooth devices, called Bluetooth Wireless Gateways (BWGs), are also IEEE 802.11 enabled so that these BWGs could serve as egress/ingress points to/from the IEEE 802.11 wireless network. We propose mitigating interference between Bluetooth and IEEE 802.11, by employing a hybrid approach of adaptive frequency hopping (AFH) and Bluetooth carrier sense (BCS) of the channels. AFH labels channels as bad or good, and Bluetooth devices only access those channels in the good state, whereas BCS is used to avoid collision by sensing the channel prior to any transmission. By combining AFH and BCS, we drastically minimize the effect of the worst-case interference scenario wherein both a Bluetooth and an IEEE 802.11 interface are co-located in a single device. BlueStar enables Bluetooth devices, belonging to either a piconet or a scatternet, to access the WAN through the BWG without the need for any fixed Bluetooth access points, while utilizing widely deployed base of IEEE 802.11 networks. Moreover, we define the protocol stack employed by BlueStar as well as indicate how BWGs efficiently manage their capacity allocation through the different systems. We also mathematically derive an upper bound on the number BWGs needed in a Bluetooth scatternet so that uninterrupted access to all Bluetooth devices could be provided.     

蓝牙通信及其安全体系

蓝牙通信技术作为一种短距离无线通信技术,将广泛应用于个人办公或商务环境中。蓝牙通信协议栈包括专为蓝牙通信开发的核心协议、借用继承协议。蓝牙规范通过各种应用轮廓来支持各种具体应用业务。蓝牙通信技术具有较完整的安全体系结构,能实现设备级的身份鉴别和授权,并能实现链路级的数据加密通信。但是,蓝牙通信技术在安全方面仍有值得思考的地方。     

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.