guidelines radio network design 1 nov rev c2

Ericsson ConfidentialGUIDELINES 1 (13)

Prepared (also subject responsible if other) No.

Jabulani KuneneApproved Checked Date Rev Reference

Jayan Thiruthiyil 2011-11-01 C

Airtel AOP Radio Network Design Guideline

1 Introduction..........................................................................................22 Inputs for Design..................................................................................23 Area Classification...............................................................................24 Capacity Guidelines.............................................................................34.1 Utilisation.............................................................................................34.2 Capacity Expansions and TRX additions.............................................44.3 New Capacity Sites..............................................................................64.4 SDCCH dimensioning..........................................................................64.5 Spectrum Utilisation.............................................................................64.6 Channel Loading Plan..........................................................................75 Antenna Selection Guidelines..............................................................76 Data Guidelines...................................................................................87 BSS guidelines.....................................................................................98 Coverage Guidelines...........................................................................98.1 New Towns Guideline........................................................................108.2 Selection of BTS................................................................................108.3 GSM Repeaters.................................................................................119 Abis Design \ Implementation Guideline............................................13





1 Introduction

This document is meant to be used as a ready reference for dimensioning the radio network and for generating the BoQ for requesting Pos. The document as such is derived from the contract and for any further detailing, the respective annexure of the contract need to be referred to.

2 Inputs for Design

A signed of AOP sheet is a pre-requisite for initiating the design process. Further site specific and node specific details should be supplementary to the above. The template for the same is attached below. The following should be checked against the present network and the trends studied, before getting into actual design phase.

REC Subscribers, HLR Registered, VLR Attached and the Ratios between REC : HLR Registered ,VLR Attached : HLR Registered and VLR Attached : REC Subscriber.

Radio mErl/ VLR Attached Subscriber and BHCA / VLR Attached Subscriber Trends

BBH:NBH Ratio

NBH and BBH Traffic trends

Present and target Radio Network Utilisation

Cell level utilization & Traffic for Grow-Degrow and Expansion / TRX addition planning along with the type of existing RBS

New towns list

Any discrepancy or major deviation on any of these should be discussed with Airtel planning teams and agreed before proceeding with design.

3 Area Classification

The areas subject to capacity/coverage expansion should fall under the classification bellow:





Platinum Towns = Political capital city, and also includes the commercial capital city if different from the political capital (Eg, examples of Platinum towns would be; Nairobi in Kenya, Lusaka in Zambia, Lagos + Abuja in Nigeria, Lilongwe + Blantyre in Malawi, Dar Es Salaam & Dodoma in Tanzania, etc)

Gold Towns = Next 4 or 3 top cities/towns (depending on whether there are 1 or 2 Platinum Cities).

Gold + Platinum cities/towns should cover the Top 5 towns (unless otherwise defined by Marketing).

Silver Towns = All other cities/towns/areas not covered by Platinum & Gold

4 Capacity Guidelines

4.1 Utilisation

Network Capacity Forecast should be governed by the subscribers forecast, Traffic Forecast in line with trends provided by the marketing teams. The Radio Network utilization is the radio capacity utilization using the below formula :

The Equipped capacity for each cell is calculated from Erlang-B with GS of 2% on the TCHs derived from the below formula.

TCH=l xTRX*8-BCCH-n x SDCCH-m x FPDCH

Where:

Where l is the number of TRX, n is the number of the SDCCH timeslots, and m is the number of dedicated data timeslots

Below is quick guide table for equipped capacity based on different configuration





Sr No

Site Configurat

ionErlangs Per Site

Erlangs Per Site

Erlangs Per Site

Erlangs Per Sector

Erlangs Per Sector

Erlangs Per Sector

sd

With 0 dedicated TS

With 1 dedicated TS

With 2 dedicated TS

With 0 dedicated TS

With 1 dedicated TS

With 2 dedicated TS

1 (1,1,1) 1 6.83 4.97 3.28 2.28 1.66 1.092 (2,2,2) 1 24.6 22.21 19.85 8.2 7.4 6.623 (3,3,3) 1 44.7 42.12 39.54 14.9 14.04 13.184 (4,4,4) 2 63.12 60.45 57.81 21.04 20.15 19.275 (5,5,5) 2 84.75 82.02 79.32 28.25 27.34 26.446 (6,6,6) 2 106.83 104.04 101.28 35.61 34.68 33.767 (7,7,7) 3 126.36 123.57 120.78 42.12 41.19 40.268 (8,8,8) 3 148.92 146.1 143.28 49.64 48.7 47.769 (9,9,9) 3 171.69 168.84 165.99 57.23 56.28 55.3310 (10,10,10) 4 191.7 188.85 185.97 63.9 62.95 61.9911 (11,11,11) 4 214.71 211.83 208.95 71.57 70.61 69.6512 (12,12,12) 4 237.81 234.93 232.02 79.27 78.31 77.34

Table 1: Exhibit 10 Erlang B table

The total capacity of the network is the sum of capacity of all the cells using the above criteria.

The target utilization for planning is as follows

Platinum : <70%

Gold : < 70%

Overall Utilisation < 75% (Silver utilization to be adjusted accordingly)

Utilisation calculations shall consider the combined 900 and 1800MHZ TRX resources. MBC to be planned and no dual band BCCH to be considered

4.2 Capacity Expansions and TRX additions

Blocking to be studied on a cell level and brought to contractual levels at cell and network level. High traffic cells to be targeted first for expansion. All expansions to be done at an even TRX level i.e 2 to 4 TRXs and 4 to 6 TRX etc. at a site level. Odd configurations are allowed only by DRU splitting between two sectors beyond a minimum of 2/2/2.

All new towns to be deployed as 2/2/2 as a minimum configuration. If high traffic is expected in some sites/cells higher configurations like 2/2/4, 2//4/4 or 4/4/4 can be planned as well.

Target Half Rate traffic is as below

Platinum / Gold Towns : 10% (HR/+AMR-HR)





Silver Towns : 25% (HR/+AMR-HR)

The HR shall be triggered only when the cell utilization reaches 80% and DYMA parameters should be used to control the same and ensure minimize the HR. Cell expansions should be planned beyond the stipulated HR levels and the cells with blocking and then with highest traffic should take priority.

For Platinum and Gold, the TRX addition should be planned can be done at 70% utlisation and actual addition at 90%. Similarly, for Silver the trigger for planning is 80% and deployment is 100%

Before taking the decision to expand a cell the following should be studied

1. Neighbour cells are optimised and traffic is balanced for optimum performance

2. Possibilities of shuffling TRUS from under utilized sites should be explored before ordering fresh HW. The shuffling should be strictly as per Grow-Degrow Guideline and should consider the utilization and aging factors mentioned there in.

3. Post expansion, the utilization should not come below 30%

4. Delta addition to be in steps of two TRXs at a site level, - 2,4,6,8,10 etc…which means after a minimum configuration of 2/2/2, the sites can be expanded to 2/3/3, 2/4/2, 2/4/4 or 4/4/4 and similarly for higher configurations. Splitting of DRU is OK within the site, but the site should have a total operational TRU count which is even,

5. In Platinum and Gold towns, the TRX addition can be done at 90% and for Silver towns, the addition need to be done at 100% cell utilization

6. Coverage should not shrink after expansion. A site in uncombined mode should remain as un-combined after expansion. Beyond 6TRXs, further expansions can be with done if required with additional TRX on combined mode with OL/UL, retaining the footprint unless there already overlap from a neighboring site.

In case faulty TRUs of the existing base are being replaced, this should be taken Outside the MC/DPE scope and a separate offer need to be placed.

Once the expansion plans are frozen, the required BoQ should be arrived at by deducting the Degrow options in the network as per the Degrow-Grow Guidelines

See attached grow/degrow guide and the TRX expansion path/flow guideline





4.3 New Capacity Sites

New capacity sites can be planned if any of the below conditions are met:

1. Once the spectral limit is reached capacity offloading sites in the vicinity can be planned so that it offloads at least two heavily utilized cells in existing network

2. The new site provides coverage extension/improvement to meet the coverage threshold levels

3. The new site will capture new traffic in addition to offloading minimum two (2) over utilized cells.

4. An IBS need to be planned if heavy traffic is generated from one building

4.4 SDCCH dimensioning

The following table shall be used for initial SDCCH dimensioning while planning new sites and expansions as part of BoQ preparation. Dynamic SDCCH can be configured for additional requirements.

TRX SDCCH2 14 26 28 3

10 412 4

4.5 Spectrum Utilisation

BCCH need to be planned as 4/12 or at least 5/15. For hopping SFH with 1/1 reuse need to be implemented. Fractional load of 17 should be targeted as per the formula below :





4.6 Channel Loading Plan

The following table should be used to calculate the capacity of the new sites and expansions. Please note that the table is for 1 fixed Data TS. In case of Gold and Platinum towns appropriate Data TS to be considered. Expansion Erlangs can be derived from the difference of the respective configurations.

TR

X

SD

CC

H

EF

PD

CH

GF

PD

CH

VO

ICE

TS

ER

LA

NG

TR

X

SD

CC

H

EF

PD

CH

GF

PD

CH

VO

ICE

TS

ER

LA

NG

TR

X

SD

CC

H

EF

PD

CH

GF

PD

CH

VO

ICE

TS

ER

LA

NG

4/0/0 4 2 1 0 28 20.15 0 0 1 0 0 0.00 0 0 1 0 0 0.00 20.154/4/0 4 2 1 0 28 20.15 4 2 1 0 28 20.15 0 0 1 0 0 0.00 40.32/2/2 2 1 1 0 13 7.40 2 1 1 0 13 7.40 2 1 1 0 13 7.40 22.2062/2/4 2 1 1 0 13 7.40 2 1 1 0 13 7.40 4 2 1 0 28 20.15 34.9544/4/4 4 2 1 0 28 20.15 4 2 1 0 28 20.15 4 2 1 0 28 20.15 60.454/6/6 4 2 1 0 28 20.15 6 2 1 0 44 34.68 6 2 1 0 44 34.68 89.516/6/6 6 2 1 0 44 34.68 6 2 1 0 44 34.68 6 2 1 0 44 34.68 104.046/8/8 6 2 1 0 44 34.68 8 3 1 0 59 48.70 8 3 1 0 59 48.70 132.088/8/8 8 3 1 0 59 48.70 8 3 1 0 59 48.70 8 3 1 0 59 48.70 146.18/10/10 8 3 1 0 59 48.70 10 4 1 0 74 62.95 10 4 1 0 74 62.95 174.610/10/10 10 4 1 0 74 62.95 10 4 1 0 74 62.95 10 4 1 0 74 62.95 188.8510/12/12 10 4 1 0 74 62.95 12 4 1 0 90 78.31 12 4 1 0 90 78.31 219.5712/12/12 12 4 1 0 90 78.31 12 4 1 0 90 78.31 12 4 1 0 90 78.31 234.93

SITE ERLANGSITE CONFIG

CELL A CELL B CELL C

5 Antenna Selection Guidelines

The following points need to be considered while ordering antennas

1. Variable Electrical Tilt antennas to be ordered for Platinum and Gold towns. In silver towns, VET to be deployed if required only.

2. Where spectrum is available in two bands (900/1800), Dual Band 4 Port antenna with independent VET should be used

3. It is preferred that 3G deployment use separate 2G/3G antennas, 6 Ports triple band antenna can be used subject to lack of space and/or high tower loading

4. 65 deg Cross polar antennas should be deployed in Urban/Suburban locations

5. 33 /65 deg 21 dBi , 65 deg 18dBi, 90 deg 17dBi X polar antennas should be deployed in Rural locations (with TMA ) as per actual local planning requirement. 65 degree antennas to be used sparingly if and only if e many site exists and not coverage gap is introduced.





The list of approved antennas that can be used are given below [new antennas is being added to the list, the new list will be distributed shortly]

6 Data Guidelines

Actual number of data TS is governed by the data traffic in the cell, but for dimensioning, the following points can be considered

1. Platinum Towns – 2 EDGE FPDCH in all cells

Can go up to 3 dedicated FPDCH is required and as low as 1 Dedicated FPDCH if traffic is low

2. Gold Towns – 2 EDGE FPDCH in all cells

Can go up to 3 dedicated FPDCH is required and as low as 1 Dedicated FPDCH if traffic is low

3. Silver Towns – 1 EDGE FPDCH in all cells;

If in actual, data traffic is less than 84MB/day, an On-demand GPRS timeslot can be assigned and dedicated EDGE TS can be removed.

4. A-bis - Plan for 2 EDGE FPDCH / Cell

5. Gb – as per actual requirements but to be planned for an optimum utilization of 70%

6. Additional FPDCHs and one Dynamic TS in addition can be assigned if any of the below conditions are met.

TS Utilisation > 100MB / 24hrs

TS Utilisation > 15MB during Data BBH

Hard blocking > 2%

PDCH Utilisation > 50%

Also refer to Section 10 on Abis link capacity optimization guideline





7 BSS guidelines

RBSC locations to be planned to give optimum balance between no. of sites integrated with RBSC and Abis requirement on transmission media. I.e. Abis to be optimally planned from the perspective of OPEX and number of site dependencies on any single link.

Each remote MGW site will have co-located BSC/TRC.

BSC nodes to be planned 6 Months in advance along with other core nodes

The average BTS to BSC ratio to be 90 in the Platinum and Gold towns and 70 in the Silver towns for the new installed BTSs.

STM/ETC dimensioning should assume no LAPD concentration (worse case)

8 Coverage Guidelines

The following outdoor receive level (coverage tested with unity gain external antenna) criteria to be taken into consideration during site coverage planning. The below figures are for 98% prediction probability criteria for Platinum & Gold towns and 95% prediction probability criteria for Silver towns in cell area. The same requirement apply for 900 and 1800.

ClutterDense Urban Urban

Sub Urban Others

Platinum Towns -60 -65 -70 -80Gold Towns -65 -70 -75 -80Silver Towns -70 -75 -80 -85

COVERAGE LEVELS FOR VARIOUS CLUTTER (dBm)

Road coverage should be better than 85dBm

Coverage in basements and lifts of buildings should be better than 85dBm in hotspots. In such cases stress to plan for IBSs. Major hotels, Hospitals , shopping malls, commercial airports, corporate houses, banks, stock markets and high end/highrise apartments should be targeted for IBS deployment.

The passive components used and link budget design for the IBS sites should support 2G and 3G technologies. 3G combiner would be part of 3G scope.

Planning tool should be updated with latest mapdata , propagation parameters and latest network database. The propagation model parameters should be optimised using drive test data from NPI teams if required.





ACCMIN should be set at -105dBm throughout the network and -110 for roaming entry points and IBSs

RLT should be set 20 for non EFR/FR/HR calls 24 for AMR/HR and 32 for AMR/FR calls

8.1 New Towns Guideline

Before deploying a new site, all options for providing the coverage from existing neighboring sites should be explored (eg increase antenna heights, deploying high gain antennas, TCC & TMA). Changes in the exiting sites will be done out of the contract and material used for this will be Outside DPE.

All new towns site should have an initial configuration of 2/2/2 in uncombined mode with TMA and two degree antenna tilt to increase coverage in near field unless required by terrain.

As a general guideline, the antenna height for single site town/Rural Area should be at least 40m. Any antenna heights below 40m need to be agreed with Bharti explicitly.

For the sectors serving Highways, 33deg 21dBi antenna can be considered if coverage can be contained on a straight road

Additional new sites around a single site should be done only after studying the TA and traffic distribution in RNO.

8.2 Selection of BTS

Tower top RBS 2111 is to be used for all the rural towns since it will incur low opex due to no requirement of the Air conditioners. Opcos to check the tower loading before proceeding on tower top BTS. Tower Top BTSs should be deployed in within vendor temperature specifications.

Outdoor Cabinet BTS: For high capacity sites configurations equal or higher than 4/4/4 RUS should be used and for configuration lower than 4/4/4 below RUG should be used where forecasted traffic will not exceed this configuration. The RBS 6101, 6102, 6201 & RBS RBS6301, should be used, (Only offer RBS6601 if we can house in an existing transmission cabinet)





If the capacity requirements are high (greater than 2/2/2) Maximum efforts should be done to deploy outdoors and tower top to save on the opex. Outdoor BTSs with heat exchangers instead of Airconditioner should be deployed in rural areas due to OPEX efficiency derived from the lower power consumption. In areas of extreme heat, Outdoor BTSs should be deployed in within vendor temperature specifications and Indoor/Airconditioner solutions should be deployed only in case the vendor temperature rating is not adequate. Outdoor BTSs can be deployed under a sun canopy to shield the active equipment from direct sun and rain..

Indoor BTS: For high capacity sites configurations equal or higher than 4/4/4, RUS should be used and for configuration below 4/4/4, RUG should be used if forcasted traffic allows. The RBS 6202 & 6601 in shelters can be used in the following locations:

o Urban areas (high capacity)o Transmission hub siteso SDH sites with an ADM

Cell On Wheels (COW) should be planned for rapid deployment situations and for special events where additional coverage and capacity are needed. A minimum of 2 per OpCo need to be planned as per requirements. It would be preferred to have the RBS 6202 & 6601.

8.3 GSM Repeaters

Low power Repeaters (<19dBm) should be used cautiously and in minimum numbers to improve coverage for high revenue customers to avoid degradation of network quality. While doing so, low gain pick up antennas should be used. Where two bands of frequency is available, dual band repeaters should be used.

All materials viz. Cables, Splitters, Couplers, Panel and Omni Antennas shall be capable of working wide frequency band of 850 to 2500 MHz, so that we can utilize the same for GSM900, GSM18 and 3G frequency.

Only Airtel approved Repeaters from specified vendors below shall be used in the network; Field tunable and remote monitorable repeaters should be ordered and used in the network.

Approved Vendors: Frog Cellsat, Vedang, 4 S Telecom, Astra, Andrew or Celletra

Selection of Indoor Repeaters and Accessories

Indoor repeater

Yagi Antenna, Panel Antenna(7.5dBi), 2dBi Omni Antennas

Equal splitters





Cables & Connectors.

Output Power o Less than19 dBmo 33 dBmo >33 dBm

Frequencyo Dual band 3 to 5 humps (hump = a subset of contiguous spectrum)o Single band 900 Mhz -3 Humps

The outdoor repeaters shall be used for fringe areas that are currently covered by weak outdoor signals, to strengthen the coverage.

o No tower >20m should be used for thiso Repeaters should be perfectly mounted on a rooftop of a suitable building

in the villages using a mast/pole.o >33 dBm repeaters can be used in the remote areas to provide extended

coverage to remote areas but to be avoided in the urban areas as it will degrade the network quality

Selection of Outdoor Repeaters and Accessories Outdoor Repeater Yagi Antenna, GSM Antenna , Panel Antenna 7.5dBm (Preferable Panel

Antenna) Equal splitters Cable & Connectors Jumper cables & Adapter

Dual band 3 to 5 humps (hump = a subset of contiguous spectrum)Single band 900 Mhz -3 Humps





9 Abis Design \ Implementation Guideline

Below guideline on how to configure the LAPD concentration should be followed:

Design BOQ should cater for Abis over IP, in up to 20% of the incremental sites, but these can be deployed in existing or new network as required.

BSC HW Impact

Packet Gateway (PGW) boards are required in the BSC.

BTS HW Impact

SIU (Site integration Unit) mounted either in the RBS cabinet or in a 19” transmission cabinet outside the RBS hardware should be ordered.

Site Type LAPD Confact (Concentration Factor)

Remarks

Up to 2/2/2 4:1 To improve E1 efficiency incase of cascading

Above 2/2/2 – 4/4/4 2:1 To prevent LAPD congestion

Above 4/4/4 – 6/6/6 2:1 On non Plat/Gold, else no concentration

Above 6/6/6 No concentration

guidelines radio network design 1 nov rev c2

Engineering

capacity guidelines

data guidelines

bss guidelines

coverage guidelines

antenna selection guidelines

design process

radio merl vlr

actual design phase