Starting with AIRAC 1304, effective 04 April 2013, a new ATC position is introduced in Riga TMA.
Until this time, Riga TMA consisted of two sectors - A and B, but they were controlled by a single position - Riga Approach (EVRA_APP) on 129.92. Now during high traffic loads or at ATC discretion it can be separated in two positions - sector A (the bigger one) remains controlled by EVRA_APP, and sector B - by Riga Approach (EVRA_B_APP) on 134.85. Also lateral limits of sector B have changed a bit (see the map below; before that it was 25nm circle around RIA VOR).
Note that both positions share the same callsign - Riga Approach.
This is how those sectors look laterally:
If both APP positions are online, their duties are separated as shown above.
If there is only EVRA_APP online, it controls both sector A and sector B (as it was before).
Normally EVRA_B_APP should not be online alone, but as it might happen in Vatsim, it will be left to controllers discretion, if he also assumes control of sector A.
In typical operations, arriving aircraft can expect STARs in EVRA_APP and vectoring in EVRA_B_APP, but it might be different depending on traffic situation, controllers preferences or pilot request.
On initial contact with EVRA_APP, report:
Example: Riga Approach, Air Baltic 123, information E, LAPSA 5A, descending FL090
When changing from EVRA_APP to EVRA_B_APP, only state your callsign.
Example: Riga Approach, Air Baltic 123