GPRS stands for General Packet Radio System - you are charged by the Kb  or MB by your provider. It is always on.

YOG are  sole suppliers of the M1256-TRI  GPRS and GSM card, ( see price list) which is a TRIBAND 900,1800 Mhz and 1900 Mhz  PCMCIA card.  This fits inside the  YOG Marine MCD-70 ( pictured below) and means that the user has a permanent connection  ( subject to network availability )  to the NET with GPRS    and if this is not available, he can use the GSM element of the product.  Speeds are in region of 33k, data is charged by the minute.

• Benefits -  TRI BAND - GPRS and GSM - you need never unplug  it again ( within signal reach of land of course )!
• Disadvantages - costly without a contract.
• Sold  unlocked, without contract, and SIM free

GSM - what is it?

Global Services Mobile  network - this is a standard telephone  that we use for voice. Some have data facilites, which require a cable, or infra red, or blue tooth.   In the UK, Orange  operate 28,800 baud  data with their HSCSD service which has  been successfully running now  for the last three years. HSCSD is useful  but costs 25p/minute  or EUR 0.32/minute.  You can also  use it for 14,400 data which is free on Orange, and it will step down to 9,600 where HSCSD is not supported.  YOG prefer  cabled solutions, as the other two require fiddling with the phone before making  any type  of data call, and faxes cannot be received without further enabling and turning on  infra red or blue tooth. Infra red is very unreliable in a rough sea, and is also affected by sunlight ( very close to the same spectrum.)  This also  eats battery life.

YOG  therefore do not supply infra red or blue tooth solutions and will not  give any support to people who unwisely   tamper in this regard with our products. Just keep it cabled, and enjoy 100% reliability.