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fixeria gerrit-no-reply at lists.osmocom.orgfixeria has uploaded this change for review. ( https://gerrit.osmocom.org/c/osmocom-bb/+/17495 )
Change subject: firmware/layer1: introduce experimental PDCH support
......................................................................
firmware/layer1: introduce experimental PDCH support
This change implements basic (receive only) support of the PDCH
channels that are used in GPRS. Several coding schemes are
defined by 3GPP TS 45.003, however we can only do CS-1
for now, since it's basically an equivalent of xCCH.
In order to support the other schemes (CS2-4), we would need to
know how to configure the DSP (look at Freecalypso code?).
Change-Id: I44531bbe8743c188cc5d4a6ca2a63000e41d6189
---
M src/target/firmware/include/layer1/mframe_sched.h
M src/target/firmware/include/layer1/sync.h
M src/target/firmware/layer1/l23_api.c
M src/target/firmware/layer1/mframe_sched.c
M src/target/firmware/layer1/prim_rx_nb.c
5 files changed, 71 insertions(+), 1 deletion(-)
git pull ssh://gerrit.osmocom.org:29418/osmocom-bb refs/changes/95/17495/1
diff --git a/src/target/firmware/include/layer1/mframe_sched.h b/src/target/firmware/include/layer1/mframe_sched.h
index 74e2d27..9434fc6 100644
--- a/src/target/firmware/include/layer1/mframe_sched.h
+++ b/src/target/firmware/include/layer1/mframe_sched.h
@@ -31,6 +31,9 @@
MF_TASK_TCH_H_0,
MF_TASK_TCH_H_1,
+ MF_TASK_GPRS_PDTCH,
+ MF_TASK_GPRS_PTCCH,
+
MF_TASK_NEIGH_PM51_C0T0,
MF_TASK_NEIGH_PM51,
MF_TASK_NEIGH_PM26E,
@@ -42,6 +45,7 @@
enum mf_sched_item_flag {
MF_F_SACCH = (1 << 0),
+ MF_F_PTCCH = (1 << 1),
};
/* The scheduler itself */
diff --git a/src/target/firmware/include/layer1/sync.h b/src/target/firmware/include/layer1/sync.h
index daf998b..6ed3890 100644
--- a/src/target/firmware/include/layer1/sync.h
+++ b/src/target/firmware/include/layer1/sync.h
@@ -124,6 +124,7 @@
GSM_DCHAN_SDCCH_8_CBCH,
GSM_DCHAN_TCH_H,
GSM_DCHAN_TCH_F,
+ GSM_DCHAN_PDCH,
GSM_DCHAN_UNKNOWN,
} type;
diff --git a/src/target/firmware/layer1/l23_api.c b/src/target/firmware/layer1/l23_api.c
index f55e670..e0fee84 100644
--- a/src/target/firmware/layer1/l23_api.c
+++ b/src/target/firmware/layer1/l23_api.c
@@ -78,6 +78,7 @@
uint8_t tn = chan_nr & 0x7;
uint8_t lch_idx;
enum mframe_task master_task = 0;
+ enum mframe_task second_task = 0;
uint32_t neigh_task = 0;
enum mf_type multiframe = 0;
@@ -97,6 +98,12 @@
lch_idx = cbits & 0x7;
master_task = MF_TASK_SDCCH8_0 + lch_idx;
multiframe = MF51;
+ } else if ((cbits & 0x1f) == 0x18) {
+ /* Osmocom specific extension for PDTCH and PTCCH */
+ master_task = MF_TASK_GPRS_PDTCH;
+ second_task = MF_TASK_GPRS_PTCCH;
+ /* FIXME: PDCH has different multiframe structure */
+ multiframe = MFNONE;
} else if ((cbits & 0x1f) == 0x19) {
/* Osmocom specific extension for CBCH on SDCCH/4 */
master_task = MF_TASK_SDCCH4_CBCH;
@@ -129,7 +136,7 @@
}
break;
}
- return (1 << master_task) | neigh_task;
+ return (1 << master_task) | (1 << second_task) | neigh_task;
}
static int chan_nr2dchan_type(uint8_t chan_nr)
@@ -144,6 +151,9 @@
return GSM_DCHAN_SDCCH_4;
} else if ((cbits & 0x18) == 0x08) {
return GSM_DCHAN_SDCCH_8;
+ } else if ((cbits & 0x1f) == 0x18) {
+ /* Osmocom-specific extension for PDCH */
+ return GSM_DCHAN_PDCH;
} else if ((cbits & 0x1f) == 0x19) {
/* Osmocom-specific extension for CBCH on SDCCH/4 */
return GSM_DCHAN_SDCCH_4_CBCH;
diff --git a/src/target/firmware/layer1/mframe_sched.c b/src/target/firmware/layer1/mframe_sched.c
index 9c2954c..fac84b4 100644
--- a/src/target/firmware/layer1/mframe_sched.c
+++ b/src/target/firmware/layer1/mframe_sched.c
@@ -311,6 +311,52 @@
{ .sched_set = NULL }
};
+/* See 3GPP TS 45.002, table 6 */
+static const struct mframe_sched_item mf_gprs_pdtch[] = {
+ { .sched_set = NB_QUAD_DL, .modulo = 13, .frame_nr = 0 },
+ { .sched_set = NB_QUAD_DL, .modulo = 13, .frame_nr = 4 },
+ { .sched_set = NB_QUAD_DL, .modulo = 13, .frame_nr = 8 },
+ /* NOTE: receive only task */
+ { .sched_set = NULL }
+};
+
+static const struct mframe_sched_item mf_gprs_ptcch[] = {
+ /* TODO: implement AB_PTCCH_UL for PTCCH/U */
+ /* TODO: implement NB_PTCCH_DL for PTCCH/D */
+#if 0
+ /* PTCCH/D */
+ { .sched_set = NB_PTCCH_DL, .modulo = 104, .frame_nr = 12, .flags = MF_F_PTCCH },
+ { .sched_set = NB_PTCCH_DL, .modulo = 104, .frame_nr = 38, .flags = MF_F_PTCCH },
+ { .sched_set = NB_PTCCH_DL, .modulo = 104, .frame_nr = 64, .flags = MF_F_PTCCH },
+ { .sched_set = NB_PTCCH_DL, .modulo = 104, .frame_nr = 90, .flags = MF_F_PTCCH },
+
+ /* PTCCH/U for TAI 0 .. 3 */
+ { .sched_set = AB_PTCCH_UL, .modulo = 416, .frame_nr = 12 },
+ { .sched_set = AB_PTCCH_UL, .modulo = 416, .frame_nr = 38 },
+ { .sched_set = AB_PTCCH_UL, .modulo = 416, .frame_nr = 64 },
+ { .sched_set = AB_PTCCH_UL, .modulo = 416, .frame_nr = 90 },
+
+ /* PTCCH/U for TAI 4 .. 7 */
+ { .sched_set = AB_PTCCH_UL, .modulo = 416, .frame_nr = 116 },
+ { .sched_set = AB_PTCCH_UL, .modulo = 416, .frame_nr = 142 },
+ { .sched_set = AB_PTCCH_UL, .modulo = 416, .frame_nr = 168 },
+ { .sched_set = AB_PTCCH_UL, .modulo = 416, .frame_nr = 194 },
+
+ /* PTCCH/U for TAI 8 .. 11 */
+ { .sched_set = AB_PTCCH_UL, .modulo = 416, .frame_nr = 220 },
+ { .sched_set = AB_PTCCH_UL, .modulo = 416, .frame_nr = 246 },
+ { .sched_set = AB_PTCCH_UL, .modulo = 416, .frame_nr = 272 },
+ { .sched_set = AB_PTCCH_UL, .modulo = 416, .frame_nr = 298 },
+
+ /* PTCCH/U for TAI 12 .. 15 */
+ { .sched_set = AB_PTCCH_UL, .modulo = 416, .frame_nr = 324 },
+ { .sched_set = AB_PTCCH_UL, .modulo = 416, .frame_nr = 350 },
+ { .sched_set = AB_PTCCH_UL, .modulo = 416, .frame_nr = 376 },
+ { .sched_set = AB_PTCCH_UL, .modulo = 416, .frame_nr = 402 },
+#endif
+ { .sched_set = NULL }
+};
+
/* Test TX */
static const struct mframe_sched_item mf_tx_all_nb[] = {
{ .sched_set = NB_QUAD_FH_UL, .modulo = 4, .frame_nr = 0 },
@@ -345,6 +391,9 @@
[MF_TASK_TCH_H_0] = mf_tch_h_0,
[MF_TASK_TCH_H_1] = mf_tch_h_1,
+ [MF_TASK_GPRS_PDTCH] = mf_gprs_pdtch,
+ [MF_TASK_GPRS_PTCCH] = mf_gprs_ptcch,
+
[MF_TASK_NEIGH_PM51_C0T0] = mf_neigh_pm51_c0t0,
[MF_TASK_NEIGH_PM51] = mf_neigh_pm51,
[MF_TASK_NEIGH_PM26E] = mf_neigh_pm26_even,
@@ -415,6 +464,10 @@
break;
/* Osmocom specific extensions */
+ case MF_TASK_GPRS_PDTCH:
+ case MF_TASK_GPRS_PTCCH:
+ cbits = 0x18;
+ break;
case MF_TASK_SDCCH4_CBCH:
cbits = 0x19;
break;
diff --git a/src/target/firmware/layer1/prim_rx_nb.c b/src/target/firmware/layer1/prim_rx_nb.c
index 38c7b53..c90c98c 100644
--- a/src/target/firmware/layer1/prim_rx_nb.c
+++ b/src/target/firmware/layer1/prim_rx_nb.c
@@ -126,6 +126,8 @@
/* Set SACCH indication in Link IDentifier */
if (mf_task_flags & MF_F_SACCH)
rxnb.dl->link_id = 0x40;
+ if (mf_task_flags & MF_F_PTCCH)
+ rxnb.dl->link_id = 0x80;
else
rxnb.dl->link_id = 0x00;
--
To view, visit https://gerrit.osmocom.org/c/osmocom-bb/+/17495
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Gerrit-Project: osmocom-bb
Gerrit-Branch: master
Gerrit-Change-Id: I44531bbe8743c188cc5d4a6ca2a63000e41d6189
Gerrit-Change-Number: 17495
Gerrit-PatchSet: 1
Gerrit-Owner: fixeria <axilirator at gmail.com>
Gerrit-MessageType: newchange
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