Mumbai University > Electronics and Telecommunication > Sem8 > Wireless Networks

Marks: 5 M

Year: Dec 2018

The building is divided into 3 zones: Zone A, Zone B, Zone C.

1) Zone A : Coverage Limited Area

2) Zone B : Coverage and Interference Limited Area

3) Zone C : Interference Limited Area

1) Zone A (Coverage Limited Area): Isolation the outside network in this part of the building is really good, because this part of the building is sub‐ground level.

Typical isolation is better than 70–80 dB

Careful design consideration is needed in the entrance and exit of the building.

Typical design levels for zone‐A are:

•–85dBm for 2G RxLev.

•–90dBm CPICH level for 3G.

•–87dBm RSRP level for 4G.

2) Zone B (Coverage and Interference Limited Area): It is the midsection of the building.This range is isolated from interference coming from distant micro sites by the neighboring buildings.Medium signal level is required here in order to avoid ping-pong handovers. Typical design levels for zone‐B are:

• –70dBm for 2G RxLev.

• –80dBm CPICH level for 3G.

• –75dBm RSRP level for 4G.

3) Zone C (Interference Limited Area):

It is the top most part of the high‐rise building is typically above the local clutter of neighboring buildings. The users along the perimeter of the building at the windows will have clear line‐of sight to many distant macro sites. These distant base stations will cause co‐channel interference.Distances as far as 10–20 km away from microsites can also cause interference. Users will experience high signal level in the display of the mobile, but suffer degraded service, bad voice quality, reduced data service, dropped calls or even totally lack of service, due to the high interference level.

Typical design levels for zone C are:

• –60 dBm for 2G RxLev.

• –70 dBm CPICH level for 3G

• –70 to –65 dBm RSRP level for 4G.

Beyond Zone C : For very high buildings, there is actually a zone D. In this zone the interference from the out-door network starts to decrease.