Presentation Outline

1. Background

2. Previous work

3. Urban wireless communications

4. Field trials and results

5. Conclusion and future work

Background

• Storm Patrick, which swept over the

Scandinavian peninsula in

26.12.2011.

• The worst storm in 30 years and

caused ~ 60 M€ damages to

energy companies in Finland.

• In some regions, power and mobile

connections were out of order for

two weeks.

• After the storm, Finnish government

tightened regulations concerning

communication and electricity

distribution networks’ reliability.

Scope of Electricity Distribution Network

Figure from Viola Systems’ ‘Case Vattenfall: Automating the Distribution Network’ report

Network Planning Tool (NPT)

Critical Technologies Towards 5G

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Rural Area Field Measurements

Nemo

Outdoor Viola Arctic

2G/3G

Fault Analysis One feeder down

*) Gray indicates network entities without electricity.

Downlink redundancy rasters

One substation down Several substations down

*) Color indicates the redundancy of 2G networks

Modelling of Urban Communication

• Urban mobile networks differ from rural mobile networks

– Networks are capacity limited rather than coverage limited (small cell size)

– Base station antennas are below rooftops or indoors. Buildings, walls, and

ceilings are shadowing the radio signal and causing multi-path effects

– More radio access technologies and operators available

• Mobile operators have taken different strategies in the deployment of

GSM/UMTS/LTE networks.

• Outdoor measurements and available indoor prediction models do not

give an accurate picture about indoor communication conditions (e.g. in

basement).

Analysis of Urban Area Grid Communication

Communication

network

3D terrain and

buildings

Coverage prediction fine-tuned

with measurements

Electricity

Network

Outdoor Measurements (1/4)

Measured rsrp values and reachable cell counts in LTE network

Outdoor Measurements (2/4)

Measured rscp values and reachable cell counts in UMTS network

Outdoor Measurements (3/4)

Measured rxlev_full values and reachable cell counts in GSM network

Outdoor Measurements (4/4)

Measured rssi values and reachable cell counts in WLAN network

Indoor measurements

• Three different types of indoor

environments were selected

– Old vs new building

– First floor vs basement

– Short vs long distance from a

BTS

• A mobile robot was used

indoors to provide the locations

for the measurement samples.

• Lidar and camera was used to

construct a 2D/3D model of

buildings’ interiors.

Critical Technologies Towards 5G

Indoor Measurement

Figure. Measurement in GSM, UMTS, LTE and WLAN networks. The red

circles illustrate handover locations.

Indoor Coverage (1 / 2)

Ground floor Basement

Indoor Coverage (1 / 2)

Ground floor

Indoor Coverage (2 / 2)

Indoor Coverage (2 / 2)

Indoor Coverage (2 / 2)

RSRP vs RSRQ in different environments

Indoor

Outdoor

Network latency (1 / 4)

• Network latency is one of

the key parameters.

• IEC 61850 standard

defines stringent

requirements for the

latency.

• LTE is reported to fulfill

the classes P4 – P6 (slow

automatic interactions).

Critical Technologies Towards 5G

Picture from Ericsson’s white paper “LTE for utilities”, 2013

Network latency (2 / 4)

Critical Technologies Towards 5G

Network latency (3 / 4)

Network latency (4 / 4)

Conclusion

• Operators have taken different strategies to deploy different radio access technologies (LTE-800/1800, GSM-900/1800, UMTS-900/2100, and WiFi-2.4/5.0) especially indoors.

• Changes in the radio environment are more vivid in urban areas due to the shadowing of buildings and the use of lower antenna heights.

• Indoor coverage prediction is challenging. It requires detailed information about building’s interiors.

• In addition to availability and reliability, latency is also a key parameter. It is affected by the network load and connection activity. The mobile network tends to release radio resources if the connection is not active.

Future work

• Performing LTE-800 field trials in rural and urban areas.

• Evaluating latencies with different packet sizes and

transmission intervals.

• Testing GOOSE traffic over a wireless link, and parallel

multi-operator and multi-RAN links to increase reliability.

• Studying new features of LTE (rel 12 and 13) to reduce

latency and to increase reliability and robustness.

– SON (Self-organizing networks) to minimize fault effects

– ProSe (Proximity Services for Public Safety) for reliability

– SDN (Software Defined Networks) for network virtualization

Thank you for your time

Any questions?

Seppo.Horsmanheimo@vtt.fi