AIRTIMEWhat is the SpaceChecker Satellite Data Service?
SpaceChecker offers a 2-way narrowband data communication service via satellite, the Satellite Data Service (SDS). To maximise cost efficiency in order to offer a high-quality but low-cost service to its customers, SpaceChecker has defined a set of airtime services with different characteristics and pricing. These services can be used separately or in combination, depending on what is best for the customer.
Please contact Spacechecker for additional information.
How does the SpaceChecker airtime work?
To minimize the cost of data communication, the following 2 parameters are crucial:
Tthe data traffic over a satellite return channel is cheaper than over the forward channel. Therefore the use of the 1-way return channel should be optimized. This is the trajectory from the (mobile) user in the field towards the (fixed) data center, or User Home Base.
The available channel capacity should be used to the maximum, and the lost capacity due to protocol overhead should be reduced to a minimum. Depending on how the data transfer is done, the amount of bits and bytes that can be transported through a channel can differ strongly. For this reason SpaceChecker promotes the use of prescheduled communication.
Prescheduled or synchronized communication is based upon accurately timed transfer of data, thanks to the GPS time signal. This way, the transmission by a modem of a data package and its reception by the base station can be perfectly synchronized. Prescheduled messages can be packed densely within the satellite channel so that little capacity is wasted.
Event-type or asynchronous communication occurs randomly and instantaneously. It requires a network protocol including acknowledgements by the receiving end to avoid loss of data. This implies full 2-way communication with the use of the (costly) forward channel. On top, the effective channel loading is limited to less than 30%.
Please contact Spacechecker for additional information.
Why is the SpaceChecker SDS system not completely event based?
The SDS-system is a narrowband communication system, basically designed for applications requesting to send on regular short intervals small data packets. For this reason, events have been added to the system as an option and not as a standard system.
Please contact Spacechecker for additional information.
What kind of events can I send?
SDS offers 2 kind of events : events and alerts. Events are not acknowledged messages send in a common used channel for all modems and without any network aknowledgement. Alerts are network acknowledged messages and are negotiated with the basestation. Triggers for alerts and/or events can be input changes, position changes, etc.
Please contact Spacechecker for additional information.
How can I still get a status when my vehicle is out of coverage?
As a direct view to the sky is an absolute requirement to get a clear communication, it is not possible to get status updates when there is no coverage like in tunnels or within buildings/warehouses. A store and forward feature is available to store the critical information in those cases and which will be transmitted as soon as coverage is again available.
Please contact Spacechecker for additional information.