Hi Vadim and others,
given how long L1CTL has been around, and how many programs implement
it by now, I really would like to ensure backwards compatibility without
introducing weird breakage all over the place.
The good news: I think it's possible to extend L1CTL in a
backwards-compatible way, and I started with a related implementation.
Some of my raw notes below:
---
Extension of L1CTL in a compatible way
* enhance l1ctl_reset with version and feature bitmap
** used by L1CTL_RESET_CONF, possibly also REQ, IND
** old implementation ignores trailer
** new implementation recognizes new format due to longer message (and enables use of new
features)
* new DM_EST_2_REQ
** sent by L23 only if feature-bit was set in RSEET_CONF
** contains additional fields
*** L1 SAPI bitmask
*** sync_source member to select own cell or neighbor cell sync info
* new DM_EST_2_CONF
** response to _REQ (which is currently missing from DM_EST_REQ)
* extend l1ctl_neigh_pm_ind with new fields at end
** L23 can use size to determine if new fields exist or not
* new DM_MODIFY_REQ
** sent by L23 to change L1 SAPI bitmask
* new DM_MODIFY_CONF to confirm it
/* bit definitions for individual features communicated in RESET_CONF */
enum l1ctl_feature {
L1CTL_FT_DM_EST2_MODIFY, /* DM_EST_2 and DM_MODIFY procedures */
L1CTL_FT_RACH_DM, /* RACH can be sent in dedicated mode */
L1CTL_FT_EXT_RACH_REQ, /* Extended RACH (11bit) support */
L1CTL_FT_SPKR_MIC, /* Hardware Speaker + Microphone supported */
L1CTL_FT_TRAFFIC_IND,
L1CTL_FT_BURST_IND,
L1CTL_FT_TBF, /* support for TBF_CFG and DATA_TBF procedures */
L1CTL_FT_SIM_SLOT, /* physical SIM slot exists */
L1CTL_FT_SIM_SLOT, /* physical SIM slot exists */
L1CTL_FT_BAND_850,
L1CTL_FT_BAND_900,
L1CTL_FT_BAND_1800,
L1CTL_FT_BAND_1900,
L1CTL_FT_CIPH_A51,
L1CTL_FT_CIPH_A52,
L1CTL_FT_CIPH_A53,
};
---
I won't go "full steam ahead" on this, but will try to get it
implemented within the next week or so.
Regards,
Harald
--
- Harald Welte <laforge(a)gnumonks.org>
http://laforge.gnumonks.org/
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