1‐Macro sites
- Bad coverage; especially for dense area.-
- Very hard to tune traffic to be dedicated for a certain indoor
2‐Micro sites
- Depending on the penetration of the micro sites indoor coverage can be achieved.
- Bad coverage; but better than macro sites
- Hard to tune traffic to be dedicated for a certain indoor
3‐Dedicated indoor solution (DAS)
Indoor planning process :
1-Demand
2-Capacity Dimensioning
3-Choice of antenna and RBS system
4-Antenna distribution
5-Freq plan
1‐Need for indoor sites (Demand)
1-Capacity :
-A certain potential building for traffic; can have a dedicated indoor
solution; though it might experience a good coverage level.
-The solution in addition to adding a new traffic (profit); provide a
relaxation in the capacity for the outdoor macro sites (capacity hot spots)
2-Coverage:
-For dense area; and due to building high density; indoor coverage may be lost though the site to site distance may reach; the only solution to provide an (every where coverage) is to dedicate an indoor solution.
- Needed for also complicated buildings (mega hotels; international air ports ….etc).
- Very critical for roaming excepted areas.
- The demand for indoors is increase as the power budget equation became more critical (higher technologies GPRS, EDGE …etc).
2-Quality:
- A dedicated solution for overcoming quality problem (Pilot pollution)
- Practically proven to add new traffic to the network.
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2‐Capacity Dimensioning :
Capacity figure per user is assumed for the indoor dimensioning
*High assumption for the in public building.
* Very high assumption for the in business building with lower GOS (0.5‐1%)
- Very High figures is assumed for the signalling dimensioning.
- Cell splitting for the high capacity building.
3‐Choice of antenna and RBS system
1‐Distrubted antenna
2‐Integrated antenna
One antenna is integrated in the Cab (special case of the disturbed antenna )
3‐Radiating cable (leaky feeder)
Special cable that act as a series of consecutive antennas.
More expensive; yet more flexible in design than normal antenna.
-Suitable for special pattern of coverage (tunnels; elevators….etc).
-Two types of losses associated with this type of feeders.
-Longitudinal loss (similar as normal feeder loss).
-Coupling loss (similar as normal antenna loss).
4‐Antenna distribution
Determine the design level of the signal strength
-Same as the coverage dimensioning of the macro sites.
-Practically depending on the level of the macro sites interference.
-Taking into consideration the expected data usage (C/I higher for a better through put).
- Practical values.
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Strategy for antenna distribution
1‐Few antennas with high power
2‐Many antennas with low power
- Better capacity situation.
-Obtain a uniform coverage pattern.
-Reduce interference to outdoor network.
Killer Mobile Effect
Strategy for connecting antennas for the RBS
1‐Passive system
-Using normal cables; splitters (equally losses disturbed) and tappers (un equally losses tappers)
-less expensive
‐ Adding big losses for the system (suitable for small and medium indoors)
2‐Active system
- Fiber Cables , repeater , or Eathernet Sysytem may be used.
-more expensive
‐ Adding low losses for the system (suitable for big and huge indoors)
3‐Hybrid solution where active & passive system may be used together
Use practical survey measurement to fine tune the antenna positioning
• Tools used
– Tems transmitter.
– Tems Receiver.
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Assumption may be verified to achieve the target signal strength (tappers instead of splitters….active distribution instead of passive….high output power RBS …etc).
3‐Antenna positioning guidelines
-Antennas to be placed in a zigzag manner for single cell indoors to achieve even coverage distribution
- Antennas to be placed over each other in multiple cells indoors to avoid
interference
More antennas needed in high floors to
overcome strong Macro interferes
-Avoid spill over with the outdoor macros
-No diversity in the uplink is needed.
5‐Freq plan
Using the first carrier (Macro Freq)
-Power dominance factor.
- Soft handover impact on Capacity Dimention.
-Spill over Calculations .
Using the Second Carrier
-Much Complex in parameter settings
-better quality and ECNO
-Further extensions in Macro layer should be taken into consideration
