A method and system for increasing the signal margin of a radiocommunication link to provide a short message service which is reliable, even under non-ideal conditions. According to the method, an increase in transmission power is used in combination with bit repetition to increase signal margin without complications in the mobile unit design, significant delay, or co-channel interference. Where a more significant increase in signal margin is desired, when a longer message is required, or for voice messages, the message may be stored and the mobile unit alerted of the message.