syncronized network

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Limited Internal NPI Training - Voice Quality 2005-09-301

Synchronized Radio Networks

– Synchronized Networks

Provides synchronization among a cluster of cells or all cells within a GSM network.

Benefits of network synch with proper frequency planning:– Possible to avoid interference between two close cells– Manage allocation of interference based on traffic distribution,

move the interference away from critical areas– Better performance gain for IRC compared to an asynchronous

network– Synchronization aids in the identification of the neighboring

cells, which is needed for HO and location measurements


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Synchronized Radio NetworksC/I – Synchronized Networks

Frame Synchronization between cells belonging to different sites is possible

MAIO Planning is not restricted to the site

ICDM (Inter Cell Dependency Matrix) can be used to identify interfering cells

Hopping Sequence NumberMobile Allocation Index Offset

Hopping Sequence NumberMobile Allocation Index Offset

Before R10, i.e. only site synchronizationBefore R10, i.e. only site synchronization

- R10, all sites synchronized- MAIO plan between any cells- R10, all sites synchronized- MAIO plan between any cells


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Synchronized Radio Networks

C/I – Synchronized Networks

A Synchronized Radio Network is possible to deploy on a small scale within a limited area or on a grand scale over a larger area

Synchronization of cells in a GSM radio network is realized per:

– TG – Co-sited TG Cluster – Radio Network


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Transceiver Group Synchronization

C/I – Transceiver Group Synchronization

TG Synch maintains synchronization of all channels within a cell.

TG Synchronization allows:– one cell to be served by one TG or a TG cluster comprising co-

located TG – synchronization of a number of adjacent cells served by one or

more co-located TG Synchronization source can be either PCM, Optional

Internal Oscillator, GPS or other TG


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C/I – TG Synchronization

Synchronization of bursts in cells realized by one TG or one TG cluster


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Synchronization of bursts in cells realized by multiple TGs or TG clusters


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Synchronization of bursts realized by TGs in multiple sites


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Transceiver Group SynchronizationC/I – TG Synchronization

GPS as a common source for calculation of nominal position The number of GPS receivers per site could be minimized with TG

cluster synchronization so that only the master TG needs to have a GPS receiver connected.

The master TG is Frame Synchronized to the Nominal Position and all the slave TGs are Frame Synchronized to the master TG


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The start position of each TDMA frame is aligned in time to the nominal start position.

The start position of the transmitted TDMA frames is synchronized between the cells

The start position in one cell does not drift in time relative the start position in the other cell.


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Planning of the FN offset introduces a difference in frame number offset between two cells

Planning of the FS offset introduces a difference in the frame start offset between two cells that are synchronized to the Nominal Position


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Synchronized Network Planning

C/I – Synchronized Network Planning

Planning of frequencies, HSN, FN offset and MAIO to utilize the advantages of synchronized cells needs to be done.

This could be based on different strategies.1. Fixed HSN and planned FN offset 2. Planned HSN and fixed FN offset 3. Planned HSN and planned FN offset

The first strategy is recommended by Ericsson!


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HSN– Use the same HSN in all cells in the synchronized area– Use a non-zero HSN

FNOFFSET– The FN Offset is used to set different positions in the Hopping

Sequence to cells using the same non-zero HSN– Avoid FN Offsets that are any multiple of 51 or close to 51– Avoid FN Offsets that are multiple of 13 if DTX is used– Locating performance is improved in cells using a shift in the

FN Offset. Synchronization to different neighbors becomes easier.


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MAIO– Use MAIO Planning in cells using the same HSN and FN Offset

to avoid using the same frequency at the same time

TSC– Assign different TSC to potential co-channel interferers– Same TSC within a MAIO cluster to free up TSCs when

synchronizing the network– The TSC is generally controlled by the BCC parameter. – The TSC parameter is only possible to configure directly in an

OL/UL subcell structure.


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FSOFFSET– A difference of 40 is needed for co-channel co-TSC

combination


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C/I – Synchronized Network Planning with SYROX

SYROX– Provides better performance and prevents errors during manual

planning

SYROX requires following inputs,– R10 or R11 (TSC recommendation requires R11)– Synchronization Cluster(s), where each cell have at least one

Channel Group that frequency hop over one specific Frequency Hopping Set

– An ICDM created by FAS, during peak hours and should be accumulated for a couple of weekdays


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SYROX algorithm generate the following for one Synchronization Cluster at a time:

– HSN (Hopping Sequence Number) – FNOFFSET (Frame Number Offset) – MAIO List (Mobile Allocation Index Offset List) – Since MAIO values will be assigned by SYROX for each

Transceiver it is very important that the values of NUMREQBPC reflect the current situation in the network

– TSC (Training Sequence Code, R11 needed)


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SYROX procedure: Start RNO from the OSS-RC workspace menu, or from

ONE (OSS Network Explorer)

With SYROX, the following tasks can be performed:

– Handling synchronization clusters Click Options -> SYROX Synchronization Clusters

– Generating SYROX result Click Tools -> SYROX Generate Result.


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With SYROX, the following tasks can be performed:– Open the SYROX Recommendation Report

Select a SYROX result in the Recording Results tab in the RNO main window

Click Reports -> SYROX -> SYROX Recommendation Report.

Synchronization Cluster MAIO Cluster Cell Name Channel Group HSN FNOFFSETTSC MAIO ListBSS_sync_DC_29 1 DCBSC56/WAC037C 1 2 0 0 0,6,11BSS_sync_DC_29 1 DCBSC56/WAC037C 2 2 0 0 17,23BSS_sync_DC_29 1 DCBSC56/WAC039B 1 2 0 0 20,10,1BSS_sync_DC_29 1 DCBSC56/WAC057C 1 2 0 0 16,3BSS_sync_DC_29 2 DCBSC56/WAC057A 1 2 28 7 18,5BSS_sync_DC_29 2 DCBSC56/WAC081A 1 2 28 7 6,19BSS_sync_DC_29 2 DCBSC56/WAC081B 1 2 28 7 2,12,21BSS_sync_DC_29 2 DCBSC56/WAC081C 1 2 28 7 10


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Synchronized Network PlanningC/I – Synchronized Network Planning with SYROX

A view of both the input data and output data of the SYROX algorithm


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C/I – Synchronized Networks

The following Guideline can be used for Synchronized Network Activation

NetworkSync

syncronized network

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