| /* rlc header descriptions |
| * |
| * Copyright (C) 2012 Ivan Klyuchnikov |
| * Copyright (C) 2012 Andreas Eversberg <jolly@eversberg.eu> |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License |
| * as published by the Free Software Foundation; either version 2 |
| * of the License, or (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| */ |
| #pragma once |
| #ifdef __cplusplus |
| extern "C" { |
| #endif |
| |
| #include "coding_scheme.h" |
| #include <osmocom/core/endian.h> |
| |
| #ifdef __cplusplus |
| } |
| #endif |
| |
| #include <stdint.h> |
| #include <string.h> |
| |
| #define RLC_GPRS_SNS 128 /* GPRS, must be power of 2 */ |
| #define RLC_EGPRS_SNS 2048 /* EGPRS, must be power of 2 */ |
| #define RLC_MAX_SNS RLC_EGPRS_SNS |
| #define RLC_MAX_LEN 74 /* MCS-9 data unit */ |
| |
| /* |
| * EGPRS resegment status information for UL |
| * When only first split block is received bsn state |
| * will be set to EGPRS_RESEG_FIRST_SEG_RXD and when |
| * only second segment is received the state will be |
| * set to EGPRS_RESEG_SECOND_SEG_RXD. When both Split |
| * blocks are received the state will be set to |
| * EGPRS_RESEG_DEFAULT |
| * The EGPRS resegmentation feature allows MS to retransmit |
| * RLC blocks of HeaderType1, HeaderType2 by segmenting |
| * them to 2 HeaderType3 blocks(Example MCS5 will be |
| * retransmitted as 2 MCS2 blocks). Table 10.4.8b.1 of 44.060 |
| * explains the possible values of SPB in HeadrType3 for UL |
| * direction. When the MCS is changed at the PCU, PCU directs the |
| * changed MCS to MS by PUAN or UPLINK ASSIGNMENT message along |
| * with RESEGMENT flag, Then MS may decide to retransmit the |
| * blocks by resegmenting it based on Table 8.1.1.1 of 44.060. |
| * The retransmission MCS is calculated based on current MCS of |
| * the Block and demanded MCS by PCU. Section 10.3a.4.3 of 44.060 |
| * shows the HeadrType3 with SPB field present in it |
| */ |
| enum egprs_rlc_ul_reseg_bsn_state { |
| EGPRS_RESEG_DEFAULT = 0, |
| EGPRS_RESEG_FIRST_SEG_RXD = 0x01, |
| EGPRS_RESEG_SECOND_SEG_RXD = 0x02, |
| EGPRS_RESEG_INVALID = 0x04 |
| }; |
| |
| /* |
| * EGPRS resegment status information for DL |
| * When only first segment is sent, bsn state |
| * will be set to EGPRS_RESEG_FIRST_SEG_SENT and when |
| * second segment is sent the state will be |
| * set to EGPRS_RESEG_SECOND_SEG_SENT. |
| * EGPRS_RESEG_DL_INVALID is set to 8 considering there is a scope for |
| * 3rd segment according to Table 10.4.8b.2 of 44.060 |
| * The EGPRS resegmentation feature allows PCU to retransmit |
| * RLC blocks of HeaderType1, HeaderType2 by segmenting |
| * them to 2 HeaderType3 blocks(Example MCS5 will be |
| * retransmitted as 2 MCS2 blocks). Table 10.4.8b.2 of 44.060 |
| * explains the possible values of SPB in HeadrType3 for DL |
| * direction.The PCU decides to retransmit the |
| * blocks by resegmenting it based on Table 8.1.1.1 of 44.060. |
| * The retransmission MCS is calculated based on current MCS of |
| * the Block and demanded MCS by PCU. Section 10.3a.3.3 of 44.060 |
| * shows the HeadrType3 with SPB field present in it |
| */ |
| enum egprs_rlc_dl_reseg_bsn_state { |
| EGPRS_RESEG_DL_DEFAULT = 0, |
| EGPRS_RESEG_FIRST_SEG_SENT = 0x01, |
| EGPRS_RESEG_SECOND_SEG_SENT = 0x02, |
| EGPRS_RESEG_DL_INVALID = 0x08 |
| }; |
| |
| /* Table 10.4.8b.2 of 44.060 */ |
| enum egprs_rlcmac_dl_spb { |
| EGPRS_RLCMAC_DL_NO_RETX = 0, |
| EGPRS_RLCMAC_DL_FIRST_SEG = 2, |
| EGPRS_RLCMAC_DL_SEC_SEG = 3, |
| }; |
| |
| /* |
| * Valid puncturing scheme values |
| * TS 44.060 10.4.8a.3.1, 10.4.8a.2.1, 10.4.8a.1.1 |
| */ |
| enum egprs_puncturing_values { |
| EGPRS_PS_1, |
| EGPRS_PS_2, |
| EGPRS_PS_3, |
| EGPRS_PS_INVALID, |
| }; |
| |
| /* |
| * EGPRS_MAX_PS_NUM_2 is valid for MCS 1,2,5,6. |
| * And EGPRS_MAX_PS_NUM_3 is valid for MCS 3,4,7,8,9 |
| * TS 44.060 10.4.8a.3.1, 10.4.8a.2.1, 10.4.8a.1.1 |
| */ |
| enum egprs_puncturing_types { |
| EGPRS_MAX_PS_NUM_2 = 2, |
| EGPRS_MAX_PS_NUM_3, |
| EGPRS_MAX_PS_NUM_INVALID, |
| }; |
| |
| static inline uint16_t mod_sns_half() |
| { |
| return (RLC_MAX_SNS / 2) - 1; |
| } |
| |
| struct gprs_rlc_data_block_info { |
| unsigned int data_len; /* EGPRS: N2, GPRS: N2-2, N-2 */ |
| unsigned int bsn; |
| unsigned int ti; |
| unsigned int e; |
| unsigned int cv; /* FBI == 1 <=> CV == 0 */ |
| unsigned int pi; |
| unsigned int spb; |
| }; |
| |
| struct gprs_rlc_data_info { |
| enum CodingScheme cs; |
| unsigned int r; |
| unsigned int si; |
| unsigned int tfi; |
| unsigned int cps; |
| unsigned int rsb; |
| unsigned int usf; |
| unsigned int es_p; |
| unsigned int rrbp; |
| unsigned int pr; |
| uint8_t num_data_blocks; /* this can actually be only 0, 1, 2: enforced in gprs_rlc_data_header_init() */ |
| unsigned int with_padding; |
| unsigned int data_offs_bits[2]; |
| struct gprs_rlc_data_block_info block_info[2]; |
| }; |
| |
| /* holds the current status of the block w.r.t UL/DL split blocks */ |
| union split_block_status { |
| egprs_rlc_ul_reseg_bsn_state block_status_ul; |
| egprs_rlc_dl_reseg_bsn_state block_status_dl; |
| }; |
| |
| struct gprs_rlc_data { |
| /* block data including LI headers */ |
| uint8_t block[RLC_MAX_LEN]; |
| /* block data len including LI headers*/ |
| uint8_t len; |
| |
| struct gprs_rlc_data_block_info block_info; |
| /* |
| * cs_current_trans is variable to hold the cs_last value for |
| * current transmission. cs_current_trans is same as cs_last during |
| * transmission case. during retransmission cs_current_trans is |
| * fetched from egprs_mcs_retx_tbl table based on |
| * cs and demanded cs.reference is 44.060 Table |
| * 8.1.1.1 and Table 8.1.1.2 |
| * For UL. cs_last shall be used everywhere. |
| */ |
| enum CodingScheme cs_current_trans; |
| enum CodingScheme cs_last; |
| |
| /* |
| * The MCS of initial transmission of a BSN |
| * This variable is used for split block |
| * processing in DL |
| */ |
| enum CodingScheme cs_init; |
| |
| /* puncturing scheme value to be used for next transmission*/ |
| enum egprs_puncturing_values next_ps; |
| |
| /* holds the status of the block w.r.t UL/DL split blocks*/ |
| union split_block_status spb_status; |
| }; |
| |
| uint8_t *prepare(struct gprs_rlc_data *rlc, size_t block_data_length); |
| |
| void gprs_rlc_data_info_init_dl(struct gprs_rlc_data_info *rlc, |
| enum CodingScheme cs, bool with_padding, const unsigned int spb); |
| void gprs_rlc_data_info_init_ul(struct gprs_rlc_data_info *rlc, |
| enum CodingScheme cs, bool with_padding); |
| void gprs_rlc_data_block_info_init(struct gprs_rlc_data_block_info *rdbi, |
| enum CodingScheme cs, bool with_padding, const unsigned int spb); |
| unsigned int gprs_rlc_mcs_cps(enum CodingScheme cs, enum egprs_puncturing_values |
| punct, enum egprs_puncturing_values punct2, bool with_padding); |
| void gprs_rlc_mcs_cps_decode(unsigned int cps, enum CodingScheme cs, |
| int *punct, int *punct2, int *with_padding); |
| enum egprs_puncturing_values gprs_get_punct_scheme(enum egprs_puncturing_values |
| punct, const enum CodingScheme &cs, |
| const enum CodingScheme &cs_current_trans, |
| const enum egprs_rlcmac_dl_spb spb); |
| void gprs_update_punct_scheme(enum egprs_puncturing_values *punct, |
| const enum CodingScheme &cs); |
| /* |
| * I hold the currently transferred blocks and will provide |
| * the routines to manipulate these arrays. |
| */ |
| struct gprs_rlc { |
| void init(); |
| gprs_rlc_data *block(int bsn); |
| gprs_rlc_data m_blocks[RLC_MAX_SNS/2]; |
| }; |
| |
| extern "C" { |
| /* TS 44.060 10.2.2 */ |
| struct rlc_ul_header { |
| #if OSMO_IS_LITTLE_ENDIAN |
| uint8_t r:1, |
| si:1, |
| cv:4, |
| pt:2; |
| uint8_t ti:1, |
| tfi:5, |
| pi:1, |
| spare:1; |
| uint8_t e:1, |
| bsn:7; |
| #elif OSMO_IS_BIG_ENDIAN |
| /* auto-generated from the little endian part above (libosmocore/contrib/struct_endianness.py) */ |
| uint8_t pt:2, cv:4, si:1, r:1; |
| uint8_t spare:1, pi:1, tfi:5, ti:1; |
| uint8_t bsn:7, e:1; |
| #endif |
| } __attribute__ ((packed)); |
| |
| struct rlc_dl_header { |
| #if OSMO_IS_LITTLE_ENDIAN |
| uint8_t usf:3, |
| s_p:1, |
| rrbp:2, |
| pt:2; |
| uint8_t fbi:1, |
| tfi:5, |
| pr:2; |
| uint8_t e:1, |
| bsn:7; |
| #elif OSMO_IS_BIG_ENDIAN |
| /* auto-generated from the little endian part above (libosmocore/contrib/struct_endianness.py) */ |
| uint8_t pt:2, rrbp:2, s_p:1, usf:3; |
| uint8_t pr:2, tfi:5, fbi:1; |
| uint8_t bsn:7, e:1; |
| #endif |
| } __attribute__ ((packed)); |
| |
| struct rlc_li_field { |
| #if OSMO_IS_LITTLE_ENDIAN |
| uint8_t e:1, |
| m:1, |
| li:6; |
| #elif OSMO_IS_BIG_ENDIAN |
| /* auto-generated from the little endian part above (libosmocore/contrib/struct_endianness.py) */ |
| uint8_t li:6, m:1, e:1; |
| #endif |
| } __attribute__ ((packed)); |
| |
| struct rlc_li_field_egprs { |
| #if OSMO_IS_LITTLE_ENDIAN |
| uint8_t e:1, |
| li:7; |
| #elif OSMO_IS_BIG_ENDIAN |
| /* auto-generated from the little endian part above (libosmocore/contrib/struct_endianness.py) */ |
| uint8_t li:7, e:1; |
| #endif |
| } __attribute__ ((packed)); |
| } |
| |
| inline void gprs_rlc::init() |
| { |
| memset(m_blocks, 0, sizeof(m_blocks)); |
| } |
| |
| inline gprs_rlc_data *gprs_rlc::block(int bsn) |
| { |
| return &m_blocks[bsn & mod_sns_half()]; |
| } |