A communication terminal unit capable of identifying a message sender by comparing a source address attached to a received message with an address registered in a memory of the unit in advance, which can identify the message sender even if the source address has an error by regarding the erroneous source...http://www.google.de/patents/US7822435?utm_source=gb-gplus-sharePatent US7822435 - Communication terminal unit capable of receiving a message and method for identifying a message sender in the same
