DAYANANDA SAGAR COLLEGE OF ENGINEERING (An Autonomous Institute Affiliated to VTU, Belagavi) Shavige Malleshwara Hills, Kumaraswamy Layout, Bengaluru-560078 Department of Information Science and Engineering (Accredited by NBA & NAAC with ‘A’ Grade) WIRELESS AND MOBILE NETWORKS 17IS8SEWMN Faculty Name: Mrs. Radhika T V Assistant professor Dept. of ISE,DSCE Dept of ISE,DSCE Module 4 Wireless Personal Area Networks Dept of ISE,DSCE Learning objectives •Tounderstandthemainphysical,architecturalandnetworkingissuesof WPAN. •To know about the design considerations of WPAN. •To study the MAC and routing protocols of WPANs. •To know about the WPAN technologies. •To illustrate the applications of WPANs. Dept of ISE,DSCE Wireless Personal Area Network(WPAN) • A personal, short distance area wireless network for interconnecting devices centered around an individual person's workspace. • Address wireless networking of mobile computing devices such as PCs, PDAs, peripherals, cell phones, pagers and consumer electronics. • Are also called short wireless distance networks. • Extends to 33 feet (10 meters) or less. • Major technologies of WPAN are Bluetooth (802.15.1), and ZigBee (802.15.4) Dept of ISE,DSCE Network architecture Consists of the Master-Slave configuration. Dept of ISE,DSCE WPAN topologies A Two connectivity topologies are defined in WPAN. • Piconet • scatternet. Dept of ISE,DSCE Piconet • A piconet is a WPAN formed by a device serving as a master and one or more devices serving as slaves in the network. Piconet Master/Slave configuration. Dept of ISE,DSCE Scatternet • A scatternet is a collection of operational piconets overlapping in time and space. • A device that is a member of two or more piconets is said to be involved in a scatternet. WPAN components • WPAN components are in a range from very low power devices with very low communication possibilities to high-end devices covering the full range of communication standards. • Requirements – The devices in a WPAN must be low cost. – The devices must operate for a long time from simple battery. – Because of their large number, they must be small such that the user is hardly aware of their presence. – The devices are small in size. – Ease of use. WPAN technologies • The IEEE 802.15 is the IEEE working group established in January 1999 to develop standards for WPAN. Bluetooth (IEEE 802.15.1) • Protocol stack Physical layer • The Baseband is the physical layer of the Bluetooth. • When the data is received, baseband checks for accuracy and extract the information from the packet. It compresses the data, packetizes using identifiers and error correction information. • The received packet is checked for errors and decompressed. Physical layer (Contd..) • The Bluetooth standard supports two types of link: – synchronous connection oriented links (SCO) – asynchronous connectionless links (ACL) • SCO is used primarily for voice communications and ACL is used for packet data. 13 different packet types are defined for the baseband layer of the Bluetooth system. Physical layer (Contd..) • The packets are – – – – – – – – – – – – – – – ID NULL POLL Frequency hopping synchronization(FHS) Data-medium rate 1(DM1) Data-high rate 1(DH1) AUX1 DM3 DH3 DM5 DH5 HV1 HV2 HV3 Data voice (DV) Physical layer specifications of 802.15 Problem 1 Problem 2 Link layer • Link management (LM) is the fourth layer of Bluetooth specification. • Each Bluetooth device has it own link manager. • It is responsible for the following functions: – To send and receive data and it is able to identify the sending device and perform authentication and ciphering functions. – It will determine what type of frame to use on a slot-by-slot • basis. – It directs how devices will listen for transmissions from other devices or put devices into various power-save modes according to the Bluetooth-specified procedures. Application software • The last basic part of Bluetooth system is application software. • The application software is set in the device that operates an application over the Bluetooth protocol stack. • This software allows the mobile phone, PDA or keyboard to do its job. • In order to interoperate with each Bluetooth devices, all of them must have compatible sections in their Bluetooth stack. IEEE 802.15.2 (Coexistence) • Concerned with coexistence issues that arise when two wireless systems share an environment of operation. • It has two goals: – to quantify the effects of mutual interference between WPAN and WLAN devices, and • to establish mechanisms for coexistence of WPAN and WLAN (e.g. IEEE 802.15.1 and IEEE 802.11b) at both the MAC and PHY layer. IEEE 802.15.2 (Contd..) • Mechanisms can be broadly categorized as collaborative or non-collaborative. – A collaborative mechanism that facilitates coexistence needs to have coordinated scheduling efforts, such as TDMA or CSMA. • Adaptive frequency hopping, MAC scheduling, and transmit power control schemes are noncollaborative mechanisms for coexistence HR-WPAN (IEEE 802.15.3) • IEEE 802.15.3 is a standard for high-rate (11 to 55 Mb/s) WPANs. • HR-WPAN mainly focus on power management, QoS and security. • The main purpose of IEEE 802.15.3 is to provide low cost, low complexity, low power consumption, and high data rate connectivity for wireless personal devices. • It is designed to support at least 11 Mbps data rate within at least 10 meters range. • The vision of HR-WPAN is “to promote wireless multimedia connectivity and interoperability between devices in a personal area network”. IEEE 802.15.3 Channels Reference model-IEEE 802.15.3 LR-WPAN (IEEE 802.15.4): ZigBee • IEEE 802.15.4 task group investigates low data rate WPAN solutions with a battery life ranging from months to several years and a very low complexity. • The spectrum allocation for this standard is as follows: 1 channel at 868 MHz, 10 channels in the 915 MHz band, and 16 channels in the 2.4 GHz band. Topology models ZigBee stack ZigBee stack (Contd..) • Physical layer: The physical layer defines radio characteristics and supports the 2.45GHz and 868/915MHz radio bands. • MAC layer uses CSMA-CA (carrier sense multiple access with collision avoidance) channel access mechanism. • Network layer performs tasks include starting the network (coordinator), assigning network addresses, adding and removing network devices, routing messages, applying security, and implementing route discovery. • Application layer consists of the Application Framework, ZigBee Device Object (ZDO), and Application Support (APS) Sublayer. IEEE 802.15.5: Mesh WPAN • A mesh WPAN employs one of two connection arrangements, full mesh topology or partial mesh topology Mesh networks have the capability to provide extension of network coveragewithout increasing transmit power or receive sensitivity, enhanced reliability via route redundancy, easier network configuration and better device battery life due to fewer retransmissions. WPAN applications • Automotive – The use of a WPAN is most suitable for vehicles as the distances between devices within the vehicles will be limited to an acceptable range and the use of cables to connect devices are cumbersome. For this reason the WPAN can be used. • Information sharing – The use of IEEE 802.15 devices has been developed for workplace use with le sharing, printing, and multimedia communications. • Home automation – The interconnectivity within the home with an increase in digitally based devices will see data transfer much more prominent. Currently using infrared communications, owners of personal digital assistants can download software to use the device as a remote control. In such application scenarios the WPAN technology is the most suitable one. WPAN applications (Contd..) • Health monitoring – With many advantages including low-power consumption, small size, simple protocol, wide compatibility, and so on, WPAN is applied to many medical applications including telemedicine system, pervasive and continuous patients monitoring and wireless-integrated medical devices. • Office automation – Notebook, printer, PDA, desktop computer, fax machine, mouse, keyboard - all can be instantly connected via Bluetooth technology. Stay completely up-to-date, at any where and any time. • RFID applications – Some of the RFID applications, using WPAN technologies finds the applications like asset tracking, people tracking, inventory tracking, etc.
