Sfh Retune Proposal
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Transcript of Sfh Retune Proposal
Introduction
The existing GSM hopping frequency plan is utilizing the lower 18 ARFCN for the hopping layer.
The hopping strategy adopted is 1/3, ie there will be 3 MAL, being used all through the
sites, with each sector having one MAL, assuming that all the sites are 3 sector sites. This
might have a number of limitations while looking at a broader aspect and the layering
concepts being used in the network. This planning provides an easy means for the
planning, having the standard allocation of MAL per sector. This has different pros and
cons from the planning and also the performance aspect.
This is capable of catering the 666 configurations utmost.
·Every cell is using the 3 MAL’s for the 3 sectors in an ordered pattern.
·When there is misaligned sector patterns this might create problems having the same hopping
channels in same area, thereby effectively affecting the re-use pattern.
The planning using the 1/3 plan will have lesser reuse pattern,
theoretically 3, but in a practical scenario it will be even less
considering the site to site distance and the sector azimuths.
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Current MAL allocation strategy
In this proposal, we will improve network performance with 1/1 strategy
(GSM & DCS).
Current Frequency PlanGSM 900 : My City Network
A BC
DE
F G
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2 11
1 1
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GSM 900 Network
• 18 BCCH Channel for all Macro.
• 18 TCH Channel for MAL Macro,
• 1 TCH as Guard Band (ARFCN 106)
• No BCCH Grouping (Pattern)
• Maximum Total Config Is 4/4/4
• 1 x 3 SFH Strategy
BCCH PlanHopping (MAL) 1x3
1
23
1
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Current Frequency PlanDCS 1800 My City Network
DCS 1800 Network
• 18 BCCH Channel for Macro.
• 18 TCH Channel for MAL Macro & IBC.
• 1 TCH as Guard Band (ARFCN 530)
• No BCCH Grouping.
• Maximum Total Config. is 4/4/4
• 1 x 1 SFH Strategy
BCCH Plan
Hopping (MAL) 1x1 Plan
1
11
1
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1
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1
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HSN current strategy
SFH (RF Hopping):
• Still using HSN 0 in RF Hopping
• Nearby Co HSN & Co MAIO will create internal interference.
BCCH & MAL (1x1) Plan
•GSM900 :
- Grouping BCCH Planning
- Cluster site-Bases BCCH Retune
- Cluster Cell-Bases MAIO Retune
•DCS1800:
- Grouping BCCH Planning
- Cluster Site-Bases BCCH Retune
- Cluster Cell-Bases MAIO Retune
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My City BSIC and HSN Plan Strategy
BSIC is maintained the same in 1 site,
means 1 Site = 3 Cells = 1 BSIC.
Put the same BSIC as far as we can.
BSIC = HSN, with formula HSN=NCC*8 +
BCC, to ease Network Maintenance.
Keep BSIC and HSN = 55 – 77 in border
area to avoid Interference between BSC.
We have used HSN = 63 for NCC=0 and
BCC =0 sites.
GSM & DCS can use the same pattern for
easy maintenance.
Flex HSN & Flex MAIO as Yes.
My City BSIC & HSN Plan Strategy
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Step1. Design NCC Plan Distribution
Step2. Arrange BCC
Step3. Obtain HSN from NCC*8 + BCC
Comparison: BCCH distribution
Before retune After retune
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900MHz
1800MHz
Almost Flat
Summary
The network city wide SFH replanning will bring in many added advantages, some underlying
benefits also. The important highights in this rework will be:
1. The Frequency allocation reuse strategy brings in the advantage of the geographical
separation between the used frequencies, basically the MAL reuse in geographically
separated sites. Thus, to some extent, we can assure the minimal internal interference by
having a wider reuse for MALs.
2. Having the same BCCH distribution for both GSM & DCS network, it will improve quality in the
some areas.
3. Clusterization of BSIC brings in efficiency in planning: - this approach generally eases the
planning procedure, there by a common pattern can be followed for all the sites. The
collocated GSM and DCS sites are assigned with same BSIC there by reducing the
complexity and site by site BSIC assignment.
4. Easiness in future planning of sites: - the extensive adding up of new sites may make the
BSIC pattern to be scattered.
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