PocketSAT: Satcom Enabled PDA via Software Radio

Status date

The objective of the project is to develop technologies and key components for a hand-held satcom packet data terminal that would operate as an accessory to a PDA. This necessitates a high degree of miniaturisation/integration of components, to an extent not traditionally pursued by the low-volume satcom market.

This project will see the development of a proof-of-concept prototype that demonstrates many key elements of the design concept, in a package not significantly larger than the target dimensions for the commercial end-product.

The key issues addressed in the project are:

1. Size/weight - how to achieve true mobility and an attractive marketable product

2. Power consumption/battery life - how to minimise power consumption and extend stand-by and operational battery life to figures that will be attractive to the marketplace

3. PDA interoperability - how to ensure one PocketSAT terminal design can be used with a variety of PDA types (it is essential for a low volume market to avoid multiple product variants)

4. Reconfigurability - how to ensure a single hardware platform can be adapted for use across a range of satcom systems/services, through software/firmware reconfiguration


There are a number of portable satcom terminals available today that can provide regional or global packet data services. However, they are generally designed for portability rather than true mobility. With the growth in demand for mobile internet access and location-based services, we believe there are market opportunities for a hand-held terminal that enables operation on the move.

Terminal manufacturers have had little motivation to strive for the necessary degree of integration to make such a product possible, given the relatively low volumes of the mobile satcom market. This project aims to 'seed' the process by developing key technologies and components that can enable the required miniaturisation and thus remove barriers to entering this emerging market sector. With suitable equipment available in the marketplace, opportunities will follow for the development and deployment of location-based services comparable to those planned for terrestrial 3G networks.

The outcomes of the work are potentially applicable to a wide range of satcom systems and service providers. Interest has already been shown by Inmarsat who are providing non-financial support to the project and are being provided with regular appraisals of progress.

Key enablers of ComSine/Giastar's solution are the application of software radio techniques, novel and highly optimised digital/RF architectures, and the rigorous application of low-power miniature components. Interoperability with a wide range of PDAs is achieved through the use of Bluetooth and/or a standard serial connection between the PDA and the PocketSAT unit.

A future production unit is anticipated to be of a planar configuration with an area matching that of a typical PDA. This unit would house all digital and RF circuitry, a battery, an integrated GPS/Galileo receiver and integrated L-band near-omni-directional antenna. It will be lightweight enough to be clipped to a PDA for mobile operation, and fold down flat against it when not in use. Alternatively it can be located nearby to the PDA and communicate with it via the wireless Bluetooth connection.

The project is planned to run from January to December 2003 and consists of the following stages:

  • Design trade-off study - to confirm the feasibility of the PocketSAT concept and to converge on a product specification and optimal architectural design. This includes a detailed paper design for a suitable near-omni-directional L-band miniature antenna.


  • PoC design and implementation - detailed design of digital and RF hardware miniaturised down to 'PDA-consistent' proportions, and development/integration of software/firmware for the transmitter and receiver of a representative satcom packet data air interface. The PoC unit will be designed to support a variety of system tests and demonstrations, and serve as a platform for further development and design optimisation.


  • Tests and Demonstrations - to validate the PoC design and to identify areas of the design needing refinement or further optimisation. Tests would be predominantly laboratory-based, however on-air field trials may also be conducted (Inmarsat have offered to support on-air testing). Certain demonstrations will be aimed at satcom system operators, service providers and/or terminal manufacturers, with a view to generating interest and financial support for a Phase 2 pre-production prototype development activity in 2004.
Current status

  • Project commenced January 2003

  • Design Review Meeting held March 2003

  • Proof-of-Concept (PoC) system design completed May 2003

  • Detailed hardware and software designs completed July 2003

  • Manufacture of PoC RF and baseband processing hardware completed September 2003

  • Transmitter and receiver baseband processing software completed December 2003

  • Real-time software/hardware and RF/baseband integration completed March 2004

  • Forward and return channel demonstrations at L-band completed April 2004

  • Final technical and commercial documentation completed June 2004

  • All final deliverables supplied and accepted: project concluded July 2004

  • Commercialisation opportunities are being actively pursued in the land-mobile, maritime and aeronautical satcom domains, both civil and military.

  • Following a successful Negotiation Meeting at ESTEC in July 2004, Phase 2 of the PocketSAT programme is due to commence in September 2004 with ESA co-funding under ARTES 4. Phase 2 will take the PoC development closer to a manufacturable end-product and will include integration of a third-party protocol stack and development of a compact antenna solution suitable for mass-production by new partner JAST Sàrl of Switzerland. Phase 2 will also include over-the-air field trials using Inmarsat satellites.