Handoff parameters

1. Handoff parameters
AJAL.A.J
Assistant Professor –Dept of ECE,
Federal Institute of Science And Technology (FISAT) TM
MAIL: ec2reach@gmail.com

2. Handoff parameters
• Word error indicator ( WEI )
• Received signal strength indication (RSSI)
• quality Indicator (QI)

3. Word error indicator ( WEI )
• This is a measure to check the output of the
demodulator in the receiver.
• When the carrier input to the demodulator is
sufficient above the threshold , the output will
be with less WEI

4. Received signal strength indication
(RSSI)
• The Received signal strength must
be around - 100 dBm

5. quality Indicator (QI)
• This is a measure of the signal quality with
respect to interference.
• Usually it is prescribed at 5 dB to 25 dB

6. Types of handoff
• The handoff can be classified into 3 categories
depending upon the strategies involved in the
handoff detection they are :
1.Mobile controlled handoff (MCHO)
2.Network controlled handoff (NCHO)
3.Mobile assisted handoff (MAHO)

7. 1.Mobile controlled handoff (MCHO)
• This is a handoff technique introduced by DECT and
north American PACES.
• In this strategy the mobile station in real time checks
the qualities of reception.
• When the qualities go below a prescribed value, it
will handoff the neighbouring cell channel carriers
for required quality.
• the mobile unit informs the MSC about a suitable
channel through which quality transmission could be
achieved.
• The handoff will be carried out as soon as it gets that
channel allotted to it.

8. 2.Network controlled handoff (NCHO)
• This technique is followed by CTZ and AMPS .
• Here the responsibility of channel quality
measurement is left with base station.
• In real time the BS measures WEI and RSSI .
• When these parameters go below the quality
mostly the BS initiates handoff through MSC.
• The MSC will allocate a free channel in the
incumbent call by suitable testing.

9. Testing!
• The procedure for testing the channel for its
freeness depends on the modulation and the
multiplexing techniques adopted in the
system.
• This kind of handoff will take relatively more
time to complete the function.

10. Processing time !
• This kind of handoff will take relatively more
time to complete the function.
• The measured values of the quality parameter
has to come from the BS’s for a final decision

11. 3.Mobile assisted handoff (MAHO)