Question: When sending a Short Message via SMS-SUBMIT with packing required, what is the maximum length of the text string provided by the UICC using the SMS default 7-bit coded alphabet?
Option 1: 140 bytes
Option 2: 160 characters (with each character encoded in 8 bits)
Option 3: 160 characters (using the SMS default 7-bit coded alphabet, packed into 8-bit octets)
Option 4: 70 characters (using the 16-bit UCS2 alphabet format)
Explanation: According to the specifications for sending Short Messages with packing required by the ME (Mobile Equipment), when using the SMS default 7-bit coded alphabet, the text string provided by the UICC (Universal Integrated Circuit Card) must not be longer than 160 characters. These characters are packed into 8-bit octets, as defined in TS 23.038 for Alphabets and language-specific information. This ensures compatibility with the SMS protocol's requirements for message length when packing is necessary.