COMMUNICATIONS (COMS)

Welcome to the COMMUNICATIONS (COMS) Team Section

Subsystem requirements

	Estimated Requirement	Requirement + contingency
Mass	205g	285g
Idle power	Unknown	x
Transmitting power	1019mW	x
Board size	8100mm² + 22mm clearance	8100mm² + 22mm clearance
Cost (components only)	~£180	~£280

Starting operating temperature range -30^oC to +60^oC

These requirements are correct as of SDD v3.

Team contacts

The Cubesat communications team consist of the following and can be contacted via e-mail.

Team advisors/mentors:
Andy Thomas ku.oc.oohay|liamsamohtydna#ku.oc.oohay|liamsamohtydna
John Heath moc.tenretnitb|aih7g#moc.tenretnitb|aih7g

Team manager - Ashley Back M6AOB: ku.ca.el|63bra#ku.ca.el|63bra

Andy Thomas' Website: http://andythomas.org.uk

INTRODUCTION TO COMS SUBSYSTEM

The primary goal of the communications subsystem is to provide a link to relay data to ground station and send commands to and from the CubeSat and as such will primarily consist of telemetry and command sequences that send and receive data respectively. Data is collected by the payload and sensors on the satellite in the form of analogue or digital data which must be sent to the ground station.

The communications subsystem (COMS) will perform two functions. It will provide the telemetry downlink and telecommand uplink functionality. The satellite will uplink and downlink in the satellite segment of the UHF amateur radio frequency band of around 435 MHz (TBC). Telemetry downlink will be provided by a 4800/2400bps PIC modem, using FSK modulation (either FFSK or GMSK), using the amateur standard AX.25 protocol. Further information on AX.25 is detailed in this file, which provides a full specification of the protocol. The system will be able to transmit 350kB in a 10 min overhead window with the 4800bps modem.