Wimax Technology

1. WiMax 802.16
SABIN SALEEM | SOE | CUSAT
S7 – ADVANCED COMPUTER NETWORKS

2. SABIN SALEEM | SOE | CUSAT
CONTENTS
What is WiMax
01
Building Block of WiMax
02
MAC Layer in Wimax
03
Security Functions
05
Conclusion
07
Services in WiMax
04
Specification & Features
06

3. What is WiMax ?
WIMAX stands for Worldwide Interoperability for Microwave
Access. WiMAX refers to broadband wireless networks that are
networks that are based on the IEEE 802.16 standard, which
ensures compatibility and interoperability between broadband
wireless access equipment.
SABIN SALEEM | SOE | CUSAT

4. • It is based on Wireless MAN technology.
• A wireless technology optimized for the delivery of IP centric services over a wide
area.
• A scalable wireless platform for constructing alternative and complementary
broadband networks.

5. SABIN SALEEM | SOE | CUSAT
IEEE 802.16: Broadband Wireless Access / WirelessMAN / WiMax
• Wireless distribution system, e.g., for the last mile, alternative to DSL
• 75 Mbit/s up to 50 km LOS, up to 10 km NLOS; 2-66 GHz band
• Initial standards without roaming or mobility support
• 802.16e adds mobility support, allows for roaming at 150 km/h
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)
802.16e (Mobile Wireless MAN)

6. SABIN SALEEM | SOE | CUSAT

7. Building Blocks
A WiMAX system consists of two
major parts −
1) A WiMAX base station.
2) A WiMAX receiver.
SABIN SALEEM | SOE | CUSAT

8. Wi MAX Base Station
• A WiMAX base station consists of indoor electronics and a WiMAX tower
similar in concept to a cell-phone tower.
• A WiMAX base station can provide coverage to a very large area up to a radius
of 6 miles.
• Any wireless device within the coverage area would be able to access the
Internet.
• The WiMAX base stations would use the MAC layer defined in the standard, a
common interface that makes the networks interoperable and would allocate
uplink and downlink bandwidth to subscribers according to their needs, on an
essentially real-time basis.
• Each base station provides wireless coverage over an area called a cell.
Theoretically, the maximum radius of a cell is 50 km or 30 miles however,
practical considerations limit it to about 10 km or 6 miles.
SABIN SALEEM | SOE | CUSAT

9. WiMax Receiver
• A WiMAX receiver may have a separate antenna or could be a stand-alone box or a PCMCIA card
sitting in your laptop or computer or any other device. This is also referred as customer premise
equipment (CPE).
• WiMAX base station is similar to accessing a wireless access point in a WiFi network, but the
coverage is greater.
SABIN SALEEM | SOE | CUSAT

10. SABIN SALEEM | SOE | CUSAT

11. SABIN SALEEM | SOE | CUSAT
MAC Layer in WiMax
• MAC was designed for point-to-multipoint broadband wireless access applications.
• The MAC layer is responsible for moving data packets to and from one Network Interface Card
(NIC) to another across a shared channel.
• The primary task of the Wi MAX MAC layer is to provide an interface between the higher transport
layers and the physical layer.
• The MAC layer takes packets from the upper layer, these packets are called MAC service data units
(MSDUs) and organizes them into MAC protocol data units (MPDUs) for transmission over the air.
• For received transmissions, the MAC layer does the reverse.

12. SABIN SALEEM | SOE | CUSAT
TDD Downlink subframe
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
TDD Uplink subframe

13. SABIN SALEEM | SOE | CUSAT

14. Type of Services by Wi Max
Non-line-of-sight Service :-
• This is a WiFi sort of service. 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
WiFi).
Line-of-sight Service:-
• In this, a fixed dish antenna points straight at the WiMAX tower from a roof top
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.

15. WiMAX - Security Functions
1. Support for Privacy
User data is encrypted using cryptographic schemes of proven robustness to provide
privacy. Both AES (Advanced Encryption Standard) and 3DES (Triple Data
Encryption Standard) are supported.
2. Device/user Authentication
The authentication framework is based on the Internet Engineering Task Force (IETF)
EAP, which supports a variety of credentials, such as
username/password, digital certificates, and smart cards.
3. Flexible Key-management Protocol
The Privacy and Key Management Protocol
Version 2 (PKMv2) is used for securely transferring keying
material from the base station to the mobile station.
SABIN SALEEM | SOE | CUSAT

16. Specifications of Wi Max
• Range - 30-mile (50-km) radius from basestation
• Speed - 70 megabits per second
• Frequency bands - 2 to 11 GHz and 10 to 66 GHz (licensed and
unlicensed bands)
Features of Wi Max
• Scalability - WiMAX has a scalable physical-layer architecture that allows for the data rate to
scale easily with available channel bandwidth.
• Quality of Service - WiMAX MAC is designed to support a large number of users, with multiple
connections per terminal, each with its own QoS requirement.
• Support for Mobility - The mobile WiMAX variant of the system has mechanisms to support
secure seamless handovers for delay tolerant full-mobility applications.

18. • Speed : Faster than broadband service.
• Wireless : Not having to lay cables reduces cost
Easier to extend to suburban and rural areas.
• Broad Coverage : Much wider coverage than WiFi
hotspots.
CONCLUSION
S A B I N S A L E E M K A L L A Y I

19. ThankFOR YOUR ATTENTION
SABIN SALEEM | SOE | CUSAT