diff --git a/libosmo-abis.spec b/libosmo-abis.spec
index 227d83f..14cf66b 100644
--- a/libosmo-abis.spec
+++ b/libosmo-abis.spec
@@ -43,13 +43,20 @@ BuildRequires:  pkgconfig(libosmovty) >= 0.3.0
 BuildRequires:  pkgconfig(ortp) >= 0.13.1
 
 %description
+In GSM, A-bis is a BSS-internal interface link between the BTS and
+BSC. This interface allows control of the radio equipment and radio
+frequency allocation in the BTS.
 
 %package -n libosmoabis4
-Summary:        A-bis interface core library
+Summary:        Osmocom A-bis interface core library
 License:        AGPL-3.0+
 Group:          System/Libraries
 
 %description -n libosmoabis4
+In the GSM system architecture, A-bis is a Base Station
+System-internal interface linking the Base Transceiver Stations (BTS)
+and Base Station Controller (BSC). This interface allows control of
+the radio equipment and radio frequency allocation in the BTS.
 
 %package -n libosmoabis-devel
 Summary:        Development files for the Osmocom A-bis core library
@@ -60,6 +67,12 @@ Requires:       libosmocore-devel >= 0.3.0
 Requires:       libosmogsm-devel >= 0.3.10
 
 %description -n libosmoabis-devel
+In GSM, A-bis is a BSS-internal interface link between the BTS and
+BSC. This interface allows control of the radio equipment and radio
+frequency allocation in the BTS.
+
+This subpackage contains libraries and header files for developing
+applications that want to make use of libosmoabis.
 
 %package -n libosmotrau0
 Summary:        Osmocom TRAU (E1/RTP) library
@@ -67,6 +80,9 @@ License:        GPL-2.0+
 Group:          System/Libraries
 
 %description -n libosmotrau0
+The Transcoder Rate Adaptor Unit enables the use of lower rates (32,
+16 or 8 kbps) over the A-bis interface instead of the 64 kbps ISDN
+rate for which the Mobile Switching Center (MSC) is designed.
 
 %package -n libosmotrau-devel
 Summary:        Development files for the Osmocom TRAU (E1/RTP) library
@@ -75,6 +91,12 @@ Group:          Development/Libraries/C and C++
 Requires:       libosmotrau0 = %version
 
 %description -n libosmotrau-devel
+The Transcoder Rate Adaptor Unit enables the use of lower bitrates
+over the A-bis interface instead of the 64 kbps design rate of the
+MSC.
+
+This subpackage contains libraries and header files for developing
+applications that want to make use of libosmotrau.
 
 %prep
 %setup -qn %name