cordect-wireless-in-local-loop-system-5798-Tao4wHg.pdf

1. corDECT
Wireless Access System
DONE BY
ANISHA BABY
NO:4

2. INTRODUCTION
corDECT is a new wireless local loop system.
Eliminate the physical connections between
telephone exchanges and subscribers.
Based on the DECT(Digital Enhanced Cordless
Technologies) standard.

3. It offers high quality voice and data
transmission.
Easier to implement ,support large
number of subscribers.
Provides simultaneous voice & internet
access.

4. Disadvantages of wired local
loop
High cost.
More faults occur.
Rapid deployment is difficult
It is expensive.
These disadvantages can be solved by using
corDECT wireless local loop.

5. Advantages of corDECT
Provides cost effective solution to local loop
problems.
Easy expansion of the network .
Provides high quality voice and data and FAX
capability.
Good speech quality .
Provides simultaneous voice and internet
access.

6. The main parts of the system are
DECT Interface Unit(DIU)
Compact Base Station(CBS)
Wallset(WS)
Handset(HS)

7. DECT Interface Unit
Performs system control.
This can cater up to 20 base stations.
It carries signal and power feed for the
base stations even up to 3kms.

8. Compact Base Station
This is the radio fixed part of the
DECT wireless local loop.
Mounted on a tower top which
can cater up to 50 subscribers.
Provides 12 simultaneous
speech channels.

9. Wallset
It is a wireless fixed terminal adaptor .
Handset
It is a portable telephone providing
voice service to a user.
It consist of two more parts
BSD-connects 4 CBS to DIU
RBS-extend the CBS coverage to
25kms.

11. Channel structure corDECT
Channel structure corDECT
20 MHz
24 Channels
12 forward channels 12 reverse channels

12. Divides its 20MHz bandwidth in to 10
frequency bands.
Each time slot is divided in to 24
channels.
So that up to 12 simultaneous calls can
be handled.

13. DECT Protocol Stack
Four protocol layers.
1. Physical (PHL) Layer
Specifies the division of 10ms frames.
Monitors quality of signal.
2. Medium Access Control(MAC)
Layer
Handles handover(bearer handover) of
a connection .

14. 3. Data Link Control(DLC) Layer
Provides connection oriented and
connectionless service.
Handles handover(connection
handover).
4. Network(NWK) Layer
Call control.
Registration & Authentication.

15. Architecture & Implementation
Micro-cellular system support high speed
data,voice telephony etc.
Features are
Frequency is selected using Dynamic Channel
Selection(DCS).
Roaming anywhere .
Authentication & Encryption.
Handover from channel to channel.

16. The DIU(exchange) consist of
1. OMC(Operation & Maintenance control )
2. SWITCH(Voice/Data Path Switching
Subsystem)
3. BIM(Base Station Interface Modules)
OMC
performs call processing .
Runs the DECT NWK layer.
System operation, maintenance ,billing .

17. SWITCH
Switching voice between subscribers.
Runs a part of the DECT DLC layer.
BIM
CBSs are connected to the DIU at the
BIM
Supports two CBS.

19. The portable runs the entire DECT
protocol stack.
Inter-Working Unit(IWU) performs
billing,registration etc.

20. Call Scenario
Sequence of events at the DECT DLC &
DECT NWK layer.
Portable A sends request to portable B.
OMC checks whether A is a valid user.
B establishes the connection.
After sometime release the connection.

22. CONCLUSION
It offers relatively low cost & rapid
installation of telecom services in areas
of even high subscriber density.
Good for highly dense urban areas.
Use telephone &internet on the same
line simultaneously.