edge: Add header type property to GprsCodingScheme

The header type depends on the coding scheme, for GPRS there is a
single data header type per direction, for EGPRS there are 3 per
direction. In addition, control block header types are used with CS-1
only, so there is one of the per direction altogether for GRPS and
EGPRS.

This commit adds the header type enum and two methods headerTypeData
and headerTypeControl.

Sponsored-by: On-Waves ehf

3 files changed, 44 insertions, 16 deletions

diff --git a/src/gprs_coding_scheme.cpp b/src/gprs_coding_scheme.cpp
index 3488b320..9fff2c91 100644
--- a/src/gprs_coding_scheme.cpp
+++ b/src/gprs_coding_scheme.cpp
@@ -27,23 +27,24 @@ static struct {
 		unsigned ext_bits;
 	} uplink, downlink;
 	const char *name;
+	GprsCodingScheme::HeaderType data_hdr;
 } mcs_info[GprsCodingScheme::NUM_SCHEMES] = {
-	{{0, 0},    {0, 0},   "UNKNOWN"},
-	{{23, 0},   {23, 0},  "CS-1"},
-	{{33, 7},   {33, 7},  "CS-2"},
-	{{39, 3},   {39, 3},  "CS-3"},
-	{{53, 7},   {53, 7},  "CS-4"},
-
-	{{26, 1},   {26, 1},  "MCS-1"},
-	{{32, 1},   {32, 1},  "MCS-2"},
-	{{41, 1},   {41, 1},  "MCS-3"},
-	{{48, 1},   {48, 1},  "MCS-4"},
-
-	{{60, 7},   {59, 6},  "MCS-5"},
-	{{78, 7},   {77, 6},  "MCS-6"},
-	{{118, 2},  {117, 4}, "MCS-7"},
-	{{142, 2},  {141, 4}, "MCS-8"},
-	{{154, 2},  {153, 4}, "MCS-9"},
+	{{0, 0},    {0, 0},   "UNKNOWN", GprsCodingScheme::HEADER_INVALID},
+	{{23, 0},   {23, 0},  "CS-1", GprsCodingScheme::HEADER_GPRS_DATA},
+	{{33, 7},   {33, 7},  "CS-2", GprsCodingScheme::HEADER_GPRS_DATA},
+	{{39, 3},   {39, 3},  "CS-3", GprsCodingScheme::HEADER_GPRS_DATA},
+	{{53, 7},   {53, 7},  "CS-4", GprsCodingScheme::HEADER_GPRS_DATA},
+
+	{{26, 1},   {26, 1},  "MCS-1", GprsCodingScheme::HEADER_EGPRS_DATA_TYPE_3},
+	{{32, 1},   {32, 1},  "MCS-2", GprsCodingScheme::HEADER_EGPRS_DATA_TYPE_3},
+	{{41, 1},   {41, 1},  "MCS-3", GprsCodingScheme::HEADER_EGPRS_DATA_TYPE_3},
+	{{48, 1},   {48, 1},  "MCS-4", GprsCodingScheme::HEADER_EGPRS_DATA_TYPE_3},
+
+	{{60, 7},   {59, 6},  "MCS-5", GprsCodingScheme::HEADER_EGPRS_DATA_TYPE_2},
+	{{78, 7},   {77, 6},  "MCS-6", GprsCodingScheme::HEADER_EGPRS_DATA_TYPE_2},
+	{{118, 2},  {117, 4}, "MCS-7", GprsCodingScheme::HEADER_EGPRS_DATA_TYPE_1},
+	{{142, 2},  {141, 4}, "MCS-8", GprsCodingScheme::HEADER_EGPRS_DATA_TYPE_1},
+	{{154, 2},  {153, 4}, "MCS-9", GprsCodingScheme::HEADER_EGPRS_DATA_TYPE_1},
 };
 
 
@@ -102,3 +103,8 @@ const char *GprsCodingScheme::name() const
 {
 	return mcs_info[m_scheme].name;
 }
+
+GprsCodingScheme::HeaderType GprsCodingScheme::headerTypeData() const
+{
+	return mcs_info[m_scheme].data_hdr;
+}
diff --git a/src/gprs_coding_scheme.h b/src/gprs_coding_scheme.h
index 71b64cf7..7ba24dec 100644
--- a/src/gprs_coding_scheme.h
+++ b/src/gprs_coding_scheme.h
@@ -40,6 +40,15 @@ public:
 		EGPRS,
 	};
 
+	enum HeaderType {
+		HEADER_INVALID,
+		HEADER_GPRS_CONTROL,
+		HEADER_GPRS_DATA,
+		HEADER_EGPRS_DATA_TYPE_1,
+		HEADER_EGPRS_DATA_TYPE_2,
+		HEADER_EGPRS_DATA_TYPE_3,
+	};
+
 	GprsCodingScheme(Scheme s = UNKNOWN);
 
 	operator bool() const {return m_scheme != UNKNOWN;}
@@ -62,6 +71,8 @@ public:
 	unsigned int spareBitsUL() const;
 	unsigned int spareBitsDL() const;
 	const char *name() const;
+	HeaderType headerTypeData() const;
+	HeaderType headerTypeControl() const;
 
 	static GprsCodingScheme getBySizeUL(unsigned size);
 
@@ -108,6 +119,11 @@ inline void GprsCodingScheme::dec(Mode mode)
 	m_scheme = new_cs;
 }
 
+inline GprsCodingScheme::HeaderType GprsCodingScheme::headerTypeControl() const
+{
+	return HEADER_GPRS_CONTROL;
+}
+
 inline GprsCodingScheme::GprsCodingScheme(Scheme s)
 	: m_scheme(s)
 {
diff --git a/tests/edge/EdgeTest.cpp b/tests/edge/EdgeTest.cpp
index ae29221c..5d4fdf76 100644
--- a/tests/edge/EdgeTest.cpp
+++ b/tests/edge/EdgeTest.cpp
@@ -129,6 +129,12 @@ static void test_coding_scheme()
 		last_size_UL = current_cs.maxBytesUL();
 		last_size_DL = current_cs.maxBytesDL();
 
+		/* Check header types */
+		OSMO_ASSERT(current_cs.headerTypeData() ==
+			GprsCodingScheme::HEADER_GPRS_DATA);
+		OSMO_ASSERT(current_cs.headerTypeControl() ==
+			GprsCodingScheme::HEADER_GPRS_CONTROL);
+
 		check_coding_scheme(current_cs, GprsCodingScheme::GPRS);
 	}
 	OSMO_ASSERT(i == 4);