Hello Harald,

On Sun, 28 Mar 2010 13:16:36 +0800, "Harald Welte" laforge@gnumonks.org wrote:

as far as I know, it has to change on every retransmission. Dieter is probably the person who knows all RACH aspects in detail, maybe he can comment on this.

According to the specification the random value has to change on every transmission:

a random reference which is drawn randomly from a uniform probability distribution for every new transmission.

In the TSM30 firmware this is done by having a table with random values and an index into the table which is initialised to a random value when the Immediate Assignment Procedure is started and incremented with every random number taken for a retransmission. The table has 32 values because the random reference is not larger than 5 bits.

Best regards, Dieter