16 October 2006 1

16 October 2006 2

Transforming London Buses RadioThe Future

David Fell

Network Architect

13 November 2014 3

Where we are – network basics

• MPT 1327 analogue trunked system

• 10 Radio sites

• 66 traffic channels

• 240 dispatcher positions in 43 control centres

• 9000 buses, 300 hand portables

• Interface with the AVL system

• System designed for the mobile radios on the buses

• Hand portables can be used but there are gaps in coverage

Where we are – usage basics

• Used for service control and emergencies.

• System was designed in 2005 with the expectation that there will be 30,000 calls per day.

• 40% increase since 2011. Current average is 55,000 calls per day peaking to over 65,000 calls during industrial action/events/major disruption.

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If the radio system fails operators can

withdraw buses from service!

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WHY WE NEED TO UPGRADEWHY WE NEED TO UPGRADE

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The next 5 years – the facts

More calls & More dispatchers

• Bus service expansion to narrow the gap with demand– 7% estimated increase in demand – 5% increase in supply

• A number of big infrastructure projects increasing the strain on London roads

• TfL needs to maintain bus excess wait time target of 1 minute

• More buses and more intervention by service controllers

We need additional capacity!

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The next 5 years – the questions

• Is commercial LTE suitable at this stage?– Redundancy and fall-back mechanisms– Access under heavy usage situations– Large number of broadcast calls

• Expand network to provide hand-portable coverage– Implications and complexity of a network providing both mobile radio

and hand portable coverage– Bus stations only or London wide?

• Carry AVL data on London Bus private network– Primary or fallback

• Digital PMR will more than double existing channel capacity in a like-for like system

– Do we need additional spectrum to cater for all the above?– Where is this spectrum going to be?

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HOW WE GET THEREHOW WE GET THERE

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The upgrade path – challenges

1. Time

•Current system already can support a very limited number of additional dispatcher positions

•Trend analysis indicates that by the end of 2016 we will not be able to support any more call volume growth.

2. Quality

•Maintain and improve quality of service– Queuing– Voice quality– Coverage

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The upgrade path – challenges

3. Migration

•Network is safety critical and live 24/7

•Large fleet size

•On frequency migration

•System integrated with AVL components, GSM is used as a fall-back

•Bus antenna challenges

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The upgrade path – requirements

Functional

• Keep current functionality and support existing AVL interface

• Generic and open interfaces for the bus radio

• Dynamic route call groups

• Increased data capabilities (are there any bottlenecks?)

• Dynamic Network management and optimisation reports and KPIs

• Ability to support an all IP connection within the vehicle

Existing digital PMR functionality will need to be enhanced

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THE NEXT 10 YEARSTHE NEXT 10 YEARS

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What the future might hold

• One TfL private radio network for primary voice communication and fallback data communication

• Commercial networks for primary data and fallback voice

• A vehicle “hub” device/modem/gateway to provide comms irrespective of carrier used (PMR/cellular/WiFi/the unknown)

• Open standards all-IP connected vehicles

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tfl.gov.uk