Stockholm Public Transportation

The resource management system BussKom and Sweden's largest private TETRA network.

StorStockholms Lokaltrafik or SL for short is the public transportation authority in the Stockholm metropolitan area. Every day close to a million commuters use one of SLs vehicles. The organisation itself is relatively small with around 500 employees but they manage a workforce of over 10 000 people through several subcontractors. SL is also responsible for developing the public transportation within the region as well as ensure that subcontractors fulfil their commitments.



The Challenge

Sometime after the turn of the millennium SL realised they lacked efficient means to manage and monitor the large workforce and the 2500 buses in the fleet. Their three separate analogue communication systems did not meet requirements anymore.

SL wanted a streamlined and dynamic management system. A solution that with support for GPS and PMR in real time could enhance control over the advanced fleet and amount of users. The system should also be able to provide updated information to customers on the internet and passengers via screens on the buses.

"- A major challenge was to develop and integrate multiple applications that met the unique requirements that our planned system entailed." - Tomas Sjöblom, Technical Project Manager at SL


After a public procurement the contract was awarded Celab Communications AB and Motorola Solutions for the delivery of a TETRA-based system including terminals, services and support.

The new system BussKom is based on Motorola’s world leading TETRA architecture, Dimetra IP. Thanks to its inherent IP technology the infrastructure ensures high performance, durability and reliability over large areas. The system extends over 33 sites that together provide adequate coverage throughout the entire area of operations. SL’s traffic control also got equipped with Motorola’s latest dispatch solution to simplify command and control.

Celab has also supplied the entire fleet of buses with Motorola mobile terminals. In order to achieve the flexibility demanded by SL, the terminals where completely integrated with a control panel from the German company INIT. The installation and integration process was managed by Celab and is key to the systems flexibility and versatility.

The control panel known as “CoPilot” is in fact a vehicle computer that increases control. It enables the driver to make announcements and present information on the on-board screens. At the traffic control centre there is a central information system that provides the screens with traffic information in real time. Through the years CoPilot has been updated and developed and is now known as BussPC.

Besides the mobile radios in the vehicles SL’s ticket inspectors, security personnel and customer service staff use Motorola handheld devices. The integrated GPS enables traffic control to monitor and dispatch the workforce more efficiently while also increasing worker safety thanks to the dedicated emergency button.

The solution has been in active service since 2003 and still provides reliable communications and efficient control. Today the system also manage communications for the regions commuter trains, ferry services and subway system.

"- Even if we faced a lot of problems initially we have overcome all issues and created an advanced system that functions very well."- Tomas Sjöblom, Technical Project Manager at SL


Celab continues to have a strong relationship with SL and have continuously delivered complementary equipment and replacement units over the years. For instance, during 2014 they supplied portable radios to all subway drivers through a contract with MTR Express which operates and maintain SL’s subway traffic.

Thanks to a long standing agreement Celab manages all service and maintenance of the information and communications system on board SL’s bus fleet. In addition to “our” own BussKom that handles voice- and data communications the contract also includes the BussPC, which manages passenger information, announcements and real time traffic updates.

A responsibility that also covers managing technological impacts following subcontractor changes. Depending on the extent of the change such transitions can lead to the reprogramming and exchange of equipment in hundreds of buses during a short period of time. Celab’s very first transition, E19, is a good example, that affected traffic in the south and east part of Stockholm. Besides re-programming equipment on 130 busses during one night it also meant preparing 242 new buses for operations in the weeks before. All new buses needed the BussPC and BussKom systems as well as cabling. And since then there have been several equally challenging transitions.