26-07-2012, 10:49 AM
WiMAX: IEEE 802.16 - Wireless MANs
[attachment=28994]
What is WiMAX?
Worldwide Interoperability for Microwave Access (WiMAX) is the common name associated to the IEEE 802.16a/REVd/e standards.
These standards are issued by the IEEE 802.16 subgroup that originally covered the Wireless Local Loop technologies with radio spectrum from 10 to 66 GHz.
WiMAX
Goal: Provide high-speed Internet access to home and business subscribers, without wires.
Base stations (BS) and subscriber stations (SS)
Centralized access control to prevents collisions
Supports applications with different QoS requirements
WiMAX is a subset of IEEE 802.16 standard
Wireless networks
Wireless PANs (Bluetooth – IEEE 802.15)
very low range
wireless connection to printers etc
Wireless LANs (WiFi – IEEE 802.11)
infrastructure as well as ad-hoc networks possible
home/office networking
Multihop Ad hoc Networks
useful when infrastructure not available, impractical, or expensive
military applications, emergencies
Physical layer
Allows use of directional antennas
Allows use of two different duplexing schemes:
Frequency Division Duplexing (FDD)
Time Division Duplexing (TDD)
Support for both full and half duplex stations
Adaptive Data Burst profiles
Transmission parameters (e.g. Modulation, FEC) can be modified on a frame-by-frame basis for each SS
Profiles are identified by ”Interval Usage Code”
Media Acces Control (MAC)
Connection oriented
Connection ID (CID), Service Flows
Channel access: decided by BS
UL-MAP
Defines uplink channel access
Defines uplink data burst profiles
DL-MAP
Defines downlink data burst profiles
UL-MAP and DL-MAP are both transmitted in the beginning of each downlink subframe
Advantages
Single station can serve hundreds of users.
Speed of 10 Mbps at 10 kilometers with line-of-site.
WiMax can run in licensed and non licensed frequencies.
Through WiMax wireless networking is possible through longer distances.
WiMax has an inner built algorithm which transfer the user to another WiMax tower. Hence overloading is reduced.
Much faster deployment of new users comparing to wired networks.
It has the capacity to offer different types of services in one platform.
WiMax is a globally accepted, technically capable, and industry-wide supported standard.
It has the capacity to offer different types of services in one platform.
It is standardized, and same frequency equipment should work together.
Disadvantages
Weather conditions like rain could interrupt the signal.
Other wireless equipment could cause interference.
Multiplied frequencies are used.
WiMAX is very power intensive technology and requires strong electrical support.
Big installation and operational coast.
Line of site is needed for longer connections.
[attachment=28994]
What is WiMAX?
Worldwide Interoperability for Microwave Access (WiMAX) is the common name associated to the IEEE 802.16a/REVd/e standards.
These standards are issued by the IEEE 802.16 subgroup that originally covered the Wireless Local Loop technologies with radio spectrum from 10 to 66 GHz.
WiMAX
Goal: Provide high-speed Internet access to home and business subscribers, without wires.
Base stations (BS) and subscriber stations (SS)
Centralized access control to prevents collisions
Supports applications with different QoS requirements
WiMAX is a subset of IEEE 802.16 standard
Wireless networks
Wireless PANs (Bluetooth – IEEE 802.15)
very low range
wireless connection to printers etc
Wireless LANs (WiFi – IEEE 802.11)
infrastructure as well as ad-hoc networks possible
home/office networking
Multihop Ad hoc Networks
useful when infrastructure not available, impractical, or expensive
military applications, emergencies
Physical layer
Allows use of directional antennas
Allows use of two different duplexing schemes:
Frequency Division Duplexing (FDD)
Time Division Duplexing (TDD)
Support for both full and half duplex stations
Adaptive Data Burst profiles
Transmission parameters (e.g. Modulation, FEC) can be modified on a frame-by-frame basis for each SS
Profiles are identified by ”Interval Usage Code”
Media Acces Control (MAC)
Connection oriented
Connection ID (CID), Service Flows
Channel access: decided by BS
UL-MAP
Defines uplink channel access
Defines uplink data burst profiles
DL-MAP
Defines downlink data burst profiles
UL-MAP and DL-MAP are both transmitted in the beginning of each downlink subframe
Advantages
Single station can serve hundreds of users.
Speed of 10 Mbps at 10 kilometers with line-of-site.
WiMax can run in licensed and non licensed frequencies.
Through WiMax wireless networking is possible through longer distances.
WiMax has an inner built algorithm which transfer the user to another WiMax tower. Hence overloading is reduced.
Much faster deployment of new users comparing to wired networks.
It has the capacity to offer different types of services in one platform.
WiMax is a globally accepted, technically capable, and industry-wide supported standard.
It has the capacity to offer different types of services in one platform.
It is standardized, and same frequency equipment should work together.
Disadvantages
Weather conditions like rain could interrupt the signal.
Other wireless equipment could cause interference.
Multiplied frequencies are used.
WiMAX is very power intensive technology and requires strong electrical support.
Big installation and operational coast.
Line of site is needed for longer connections.