Lect 5 WiMax and Bluetooth.pdf

University of Science & Technology Faculty of Computer Science & Information Technology Department of information for communication and technology Mobile communications & wireless technology_ it 709 4year/sem 7 Tawffeeg Mohammed Tawfeeg Bluetooth...

University of Science & Technology Faculty of Computer Science & Information Technology Department of information for communication and technology Mobile communications & wireless technology_ it 709 4year/sem 7 Tawffeeg Mohammed Tawfeeg Bluetooth & WiMAX  Introduction The IEEE 802.11 WiFi standard is aimed at communication among devices separated by up to 100 meters. Two other IEEE 802 protocols—Bluetooth and Zigbee (defined in the IEEE 802.15.1 and IEEE 802.15.4 standards and WiMAX (defined in the IEEE 802.16 standard are standards for communicating over shorter and longer distances, respectively. What does Bluetooth do for you? Landline Cable Replacement Data/Voice Access Points Personal Ad-hoc Networks Ultimate Headset Cordless Computer  Bluetooth An IEEE 802.15.1 network operates over a short range, at low power, and at low cost. It is essentially a low-power, short-range, low- rate ―cable replacement technology for interconnecting notebooks, peripheral devices, cellular phones, and smart- phones. Where as 802.11 is a higher-power, medium-range, higher-rate―access technology.  Bluetooth Cont. 802.15.1 networks operate in the 2.4 GHz unlicensed radio band in a TDM manner, with time slots of 625 microseconds. During each time slot, a sender transmits on one of 79 channels, with the channel changing in a known but pseudo-random manner from slot to slot. This form of channel hopping, known as frequency-hopping spread spectrum (FHSS), spreads transmissions in time over the frequency spectrum. 802.15.1 can provide data rates up to 4 Mbps. Bluetooth is ad hoc networks 802.15.1 networks are ad hoc networks: No network infrastructure (e.g., an access point) is needed to interconnect 802.15.1 devices. Thus, 802.15.1 devices must organize themselves. 802.15.1 devices are first organized into a piconet of up to eight active devices, as shown in Figure: 802.15: personal area network  less than 10 m diameter  replacement for cables (mouse, P keyboard, headphones) S  ad hoc: no infrastructure P radius of M  master/slaves: coverage  slaves request permission to S P S send (to master) P  master grants requests  802.15: evolved from Bluetooth specification M Master device  2.4-2.5 GHz radio band S Slave device  up to 721 kbps P Parked device (inactive) Wireless, Mobile Networks 6-10  WiMAX The acronym WiMAX stands for ―Worldwide Interoperability for Microwave Access‖. It is based on IEEE 802.16 standard. aims to deliver wireless data to a large number of users over wide area at rate that revival that of cable modem and ADSL networks. WiMAX (IEEE 802.16) 11  Introduction WiMAX aims to provide wireless broadband services with a target range of up to 31 miles at a transmission rate exceeding 100 Mbps. It is also to provide a wireless alternative to cable, DSL and T1/E1 for last mile access. The term IEEE 802.16 and WIMAX are used interchangeably. WiMAX is to IEEE 802.16 what Wi-Fi is to IEEE 802.11 WiMAX (IEEE 802.16) 12 WiMAX communications system and their neighborhood now and in the near future WiMax Deepak Pareek, „The Business of John Wiley & Sons, Ltd., 2006 WiMAX―,  WiMAX areas In practical terms, WiMAX would operate similar to WiFi but at higher speeds, over greater distances and for a greater number of users. WiMAX could potentially erase the suburban and rural blackout areas that currently have no broadband Internet access because phone and cable companies have not yet run the necessary wires to those remote locations.  WiMAX system A WiMAX system consists of two parts: A WiMAX tower, similar in concept to a cell- phone tower - A single WiMAX tower can provide coverage to a very large area -- as big as 3,000 square miles (~8,000 square km). A WiMAX receiver - The receiver and antenna could be a small box or PCMCIA card, or they could be built into a laptop the way WiFi access is today.  How WiMAX Works The WiMAX tower connects to the Internet using a wired connection and allows Internet traffic to flow through a wireless core network to a local base station. The WiMAX receiver—which is located on top of the business’ building—sends and receives encrypted low-frequency microwaves through a secure, dedicated wireless circuit. WiMAX system WiMAX Tower Connection A WiMAX tower station can connect directly to the Internet using a high bandwidth, wired connection. It can also connect to another WiMAX tower using a line-of-sight, microwave link. This connection to a second tower (often referred to as a backhaul), along with the ability of a single tower to cover up to 3,000 square miles, is what allows WiMAX to provide coverage to remote rural areas. Thanks for attentions These slides are adapted from Computer Networking: A Top Down Approach Jim Kurose, Keith Ross Addison-Wesley March 2012