Method for receiving and managing a downlink radio link control data block in an EGPRS mobile electronic communication device
View Patent ↗In a mobile electronic communication device for receiving a downlink radio link control (RLC) data block, the improvement comprising determining whether an Extension (E) bit within a header of the data block has been reset to zero, thereby denoting the existence of extension octets within the data block, summing the lengths of the extension octets, calculating the number of bytes in the data block, and discarding the data block in the event the sum of the lengths is greater than the number of bytes in the data block.
1. A processor implemented method comprising:
a) receiving a radio link control (RLC) data block having at least one Extension (E) bit for indicating the presence of one or more optional extension octets in the RLC data block, wherein each extension octet comprises a 7-bit length indicator (LI) for indicating the length of a Logical Link Control Protocol Data Unit (LLC PDU) that ends in that RLC data block, and a further Extension (E) bit to indicate any further optional extension octets;
b) determining a logical value of said at least one Extension (E); in the event said bit is a first logical value then
c1) calculating a sum of said length indicators (LIs) in said RLC data block;
c2) calculating a number of bytes in said RLC data block wherein the number of bytes in the RLC data block is the number of whole bytes minus the number of length indicators (LIs); and
c3) discarding said RLC data block in the event said sum exceeds said number of bytes in said RLC data block and in response executing step a); or
in the event said bit is other than said first logical value then c4) executing step a).
2. A method of managing a downlink radio link control (RLC) data block in an Enhanced General Packet Radio System (EGPRS) mobile electronic communication device, comprising:
a) receiving said downlink RLC data block;
b) determining whether an Extension (E) bit within a header of said RLC data block has been reset to zero, thereby denoting the existence of extension octets within said RLC data block, each of said extension octets including a length indicator (LI) for indicating the length of a Logical Link Control Protocol Data Unit (LLC PDU) that ends in that RLC data block;
c) in the event said Extension (E) bit has not been reset to zero then returning to a), and otherwise
d) calculating a sum of each length indicator (LI) from each of said extension octets in said RLC data block;
e) calculating the number of bytes in said RLC data block wherein the number of bytes in the RLC data block is the number of whole bytes minus the number of length indicators (LIs); and
f) in the event said sum exceeds said number of bytes then discarding said RLC data block and otherwise returning to a).
3. In a mobile electronic communication device for receiving a downlink radio link control (RLC) data block, the improvement comprising:
determining whether an Extension (E) bit within a header of said RLC data block has been reset to zero, thereby denoting the existence of extension octets within said RLC data block wherein each extension octet comprises a 7-bit length indicator (LI) for indicating the length of a Logical Link Control Protocol Data Unit (LLC PDU) that ends in that PLC data block. and a further Extension (E) bit to indicate any further optional extension octets;
summing the length indicators in each of said extension octets in said RLC data block;
calculating the number of bytes in said RLC data block wherein the number of bytes in the RLC data block is the number of whole bytes minus the number of length indicators (LIs); and
discarding said RLC data block in the event the sum of said lengths is greater than the calculated number of bytes in the RLC data block.