gsm: Provide decoding for Handover Reference and ARFCN...

2 files changed, 34 insertions, 0 deletions

diff --git a/GSM48.st b/GSM48.st
index 6c20156..db9dd9e 100644
--- a/GSM48.st
+++ b/GSM48.st
@@ -334,6 +334,31 @@ GSM48SimpleData subclass: GSM48ChannelDescription2 [
 
     <gsmName: 'channelDescription2'>
     <gsmValueLength: 3>
+
+    channelType [
+        <category: 'accessing'>
+        ^ data first bitShift: -3.
+    ]
+
+    timeSlot [
+        ^ data first bitAnd: 2r111
+    ]
+
+    isH1 [
+        ^ (data second bitAt: 5) = 1
+    ]
+
+    isH0 [
+        ^ (data second bitAt: 5) = 0
+    ]
+
+    arfcn [
+        | low |
+        self isH0 ifFalse: [^self error: 'ARFCN requires H=0'].
+
+        low := data second bitAnd: 2r11.
+        ^ (low bitShift: 8) bitOr: data third.
+    ]
 ]
 
 GSM48SimpleData subclass: GSM48ChannelMode [
@@ -426,6 +451,11 @@ GSM48SimpleData subclass: GSM48HandoverReference [
     <comment: 'I represent a 10.5.2.15 handover reference'>
     <gsmName: 'handoverReference'>
     <gsmValueLength: 1>
+
+    value [
+        <category: 'accessing'>
+        ^ data first
+    ]
 ]
 
 GSM48DataHolder subclass: GSM48MultislotAllocation [
diff --git a/Tests.st b/Tests.st
index 4866593..2b3c4fa 100644
--- a/Tests.st
+++ b/Tests.st
@@ -440,6 +440,10 @@ TestCase subclass: GSM48Test [
         self assert: dec cellDescription bcc = 7.
         self assert: dec cellDescription ncc = 7.
         self assert: dec cellDescription bcch = 809.
+        self assert: dec handoverReference value = 0.
+        self assert: dec channelDescription2 channelType = 1.
+        self assert: dec channelDescription2 timeSlot = 3.
+        self assert: dec channelDescription2 arfcn = 809.
     ]
 ]