FAQs from Rohde & Schwarz

CMW500 / CMW290: GPRS / EDGE packet data measurements failed because UE stay not in TBF (Temporary Block Flow) state


Most of smartphones are build to be always online and this will result in the behaviour that an active data connection will be setup by default. For this active data connection the phone will establish a PDP context always when it attaches to the network. But for GPRS / EDGE data measurments with the CMW callbox, the phone has to be in the so called TBF (Temporary Block Folw) state. If the phone will not stay permanent in TBF state BER / DBLER data measurement tests will fail. So how can a smartphone be prevented to establish a PDP context and to stay permanent in TBF state?

GSM connection states:

GSM connection states


There are two options to prevent a PDP context activation:

1) Switch off "data services" on the smartphone: In most of the smartphones the data services can be switched off in the network settings menue. Most but not all smartphones will deactivate the PDP context and change into TBF state. Some smartphones will only prevent the installed applications to generate data traffic and keep the PDP context.

2) Reject of PDP context activation request by CMW: If the PDP context activaton will be rejected the majority of smartphones will stay stay stabil in TBF state. This setting can be found in the GSM cell configuration (see picture below):

GSM cell configuration