Done by: Naglaa Fathi Abdulghany Bassam Mohammed Ali Supervisor Dr. Ensaf Alzurqa
What is Wimax WiMAX is a standards-based technology enabling the delivery of last mile wireless broadband access as an alternative to wired broadband like cable and DSL. WiMAX is a wireless communications standard designed to provide 30 to 40 megabit-per-second data rates, providing up to 1 Gbit /s for fixed stations.. Goal: Provide high-speed Internet access to home and business subscribers, without wires.
Wimax Design WiMAX system components: 1-Tower WiMAX Sender: Each tower covers an area of 8000 square kilometers. 2 - Tower WiMAX the Future: The form is available on the Antenna type of card or PCMCIA card.
3-Backhaul: A WiMAX tower station can connect directly to the Internet using a high-bandwidth, wired connection. Uses of Wimax Connecting Wi-Fi hotspots with other parts of the Internet. Providing a wireless alternative to cable and DSL for "last mile broadband access. Providing data and telecommunications services. Providing a source of Internet connectivity as part of a business continuity plan.
Types of WiMAX sight:-of-line-Non Where a mobile Here a small antenna on your computer connects to the WiMAX tower. In this mode, WiMAX uses a lower frequency range -- 2 GHz to 11 GHz (similar to Wi-Fi). :sight-of-Line where a fixed dish antenna points straight at the WiMAX tower from a rooftop or pole. The line-of-sight connection is stronger and more stable, so it's able to send a lot of data with fewer errors. Line-of-sight transmissions use higher frequencies, with ranges reaching a possible 66 GHz..
WiMAX s features: 1- The transfer of information at very high speed. 2- Flexible standards and tools operation, where WiMAX can be working on several types of networks with different compositions design. 3- Protection and high security where WiMAX support the following systems: (AES) Advanced Encryption Standard , as well as (DES) is Data Encryption Standard. Advantage of these systems and technology, security and the lack of a high probability of impenetrable in various stages ( transmitter .... receiver... the center carrier ).
4- Speed of employment where they can work directly WiMAX system without the need to download any software or any supplementary parts of the system and the operator can be used any package of data packets allowed within the limits of the system operational. 5- Reduced cost that is, it is relatively cost suitable for various communication systems where they are making WiMAX systems according to the measurements of the world in terms of structure engineering . 6- The broad scope of coverage by using BPSK, QPSK, 16-QAM, and 64-QAM . 7- The possibility of formation of private networks and efficiently relatively high and these networks are specific to a particular institution or organization and the Ministry of the possibility of making it easier to use a multitude (VoIP) between formations of this institution
Standards Associated With Wimax:
WiMAX is a subset of IEEE 802.16 standard -802.16.1 (10-66 GHz, line-of-sight, up to 134Mbit/s) 802.16.2 (minimizing interference between coexisting WMANs) -802.16a (2-11 Ghz, Mesh, non-line-of-sight) 802.16b (5-6 Ghz)- -802.16c (detailed system profiles) -P802.16e (Mobile Wireless MAN)
Network Model 1-Mobile Stations (MS) used by the end user to access the network. A mobile station (MS) comprises all user equipment and software needed for communication with a mobile network The subscriber station (SS) is a fixed wireless node. 2-The access service network (ASN) An access network is that part of a telecommunications network which connects subscribers to their immediate service provider. -Base Station, BS
responsible for providing the air interface to the subscriber and mobile stations multicast group management QoS policy enforcement DHCP (Dynamic Host Control Protocol) proxy session management -The ASN-GW may also provide additional functions that include intra-ASN location management and paging, radio resource management and admission control, caching of subscriber profiles and encryption keys AAA client functionality establishment and management of mobility tunnel with base stations routing to the selected CSN
Connectivity service network (CSN 1-Home Agent, HA: -for the control of the mobility -The Home Agent serves as an anchor point for subscribers, providing secure roaming with QOS capabilities 2-Dsn/DHCP -Translation of domain name into ip address -Ip address allocation 3-Authentication, Authorisation and Accounting Server, AAA - As with any communications or wireless system requiring subscription services, an Authentication, Authorisation and Accounting server is used 4-oss -customer provisioning -network monitoring and troubleshooting 5-bss charging and billing formatting
ENHANCEMENTS IN WIMAXOFDM Orthogonal Frequency Division Multiplexing, an FDM Modulation technique for transmitting large amounts of digital data over a radio wave. OFDM works by splitting the radio signal into multiple smaller sub-signals that are then transmitted simultaneously at different frequencies to the receiver. OFDM reduces the amount of cross talk in signal transmissions.802.11a WLAN , 802.16 and WiMAX technologies use OFDM. Adaptive modulation and coding (AMC): AMC is an effective mechanism to maximize throughput in a time-varying channel supports a number of modulation and forward error correction (FEC) coding schemes and allows the scheme to be changed on a per user and per frame basis, based on channel conditions.
Link-layer retransmissions: WiMAX supports automatic retransmission requests (ARQ) at the link layer for connections that require enhanced reliability. ARQ- enabled connections require each transmitted packet to be acknowledged by the receiver; unacknowledged packets are assumed to be lost and are retransmitted. Flexible and dynamic per user resource allocation: Both uplink and downlink resource allocation are controlled by a scheduler in the base station. Capacity is shared among multiple users on a demand basis, using a burst TDM scheme. Support for TDD and FDD: IEEE 802.16-2004 and IEEE 802.16e-2005 supports both time division duplexing and frequency division duplexing, as well as a half-duplex FDD, which allows for a low-cost system implementation.
Quality-of-service support: The WiMAX MAC layer has a connection-oriented architecture that is designed to support a variety of applications, including voice and multimedia services. WiMAX system offers support for constant bit rate, variable bit rate, real-time, and non-real-time traffic flows, in addition to best-effort data traffic. WiMAX MAC is designed to support a large number of users, with multiple connections per terminal, each with its own QoS requirement Robust security: WiMAX supports strong encryption, using Advanced Encryption Standard (AES), and has a robust privacy and key-management protocol. The system also offers a very flexible authentication architecture based on Extensible Authentication Protocol (EAP), which allows for a variety of user credentials, including username/password, digital certificates, and smart cards.