In the Inmarsat system it is possible to transmit an SMS (short message service). The only thing you have to keep in mind that you send it via a LES which has been controlled by a provider offering this service. When sending an SMS you have to prepare the message conforming to the prescribed protocol of the provider of the LES. One of the providers supporting this SMS service is e.g. Stratos Mobile Networks of the Netherlands. Stratos Mobile Networks offers on its web site information that tells us how to transmit a SMS via the Inmarsat C system, which is called C-SMS. Most of the time the name of a LES is called so after the name of the city or village nearby the LES; in the Netherlands this village is called Burum.
When sending a SMS to e.g. a Dutch registered mobile phone +31(0)615404564 via LES Burum operated by Stratos Mobile Networks of the Netherlands, we have to prepare the message as follows: prepare the SMS text starting with the phone number followed by a space and then the text. After preparation of the text, we should mark it in the address book as 'special' and use the special access code 'SMS' or '696'. As a LES we have to select Burum (this is the Dutch LES operated by Stratos).

Practise on the Inmarsat C simulator

• Select 'File' in the Menu bar on the top of the screen by using the arrow keys followed by 'Enter'.
• Select 'New ASCII' by using the arrow keys followed by 'Enter'.
• Now the cursor is blinking on the top of the Text field and the text can be added by typing in on the keyboard something like: 31615404564 text....
  
• When the text has been entered you can transmit it immediately (Alt,T combination to enter the transmit menu), or save it (Alt,F,S combination to enter the file 'save menu').
• Go to the address book by touching the space bar.
• Select a SMS address by using the arrow keys and press 'Enter' or add a new one to the addressbook using 'special' and fill in special access code 'SMS' or '696'.
  
• Go to Land Station using the arrow buttons and touch the 'Space Bar' and then select a Land Earth Station 'Burum' (this is the Dutch LES operated by Stratos) using the arrow keys and confirm your choice by pressing 'Enter'.
• Go to '[X] Text in editor ' using the arrow keys (by-pass this item when you wish to send your text message from the screen) touching the 'space bar' in this position will remove the mark showing '[ ] Text in editor ' and 'File:' below this field this option can be used to transmit a saved file.
  
• Go to the priority menu by using the arrow keys and select priority of message (Routine or Non Urgent) using the 'space bar'
  
• Go to the request confirmation by using the arrow keys and decide if you wish to have a delivery confimation request, which can be selected by using the 'space bar'
• Go to Print by using the arrow keys and decide if you want to print the file, which can be selected by using the 'space bar'.
• Go to immediate transmission by using the arrow keys and decide if you want a direct transmission, which can be selected by using the 'space bar' .
• Go to Send using the arrow keys and press 'enter' (or enter password if protected).
• The SMS will now be transmitted to the LES and after the successful delivery you will get a confirmation, if you've chosen this option.
• During the transmission of the message the indication light 'Send' on the transceiver is blinking and the status field on the screen shows 'Sending'.
  

The process of message delivery can be monitored in the 'transmit log'.