/* * Copyright (C) 2013 by Holger Hans Peter Freyther * * 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. */ #include "bts.h" #include "gprs_debug.h" #include #include #include #include extern "C" { #include #include #include #include "coding_scheme.h" } uint8_t *prepare(struct gprs_rlc_data *rlc, size_t block_data_len) { /* todo.. only set it once if it turns out to be a bottleneck */ memset(rlc->block, 0x0, sizeof(rlc->block)); memset(rlc->block, 0x2b, block_data_len); /* Initial value of puncturing scheme */ rlc->next_ps = EGPRS_PS_1; return rlc->block; } static void gprs_rlc_data_header_init(struct gprs_rlc_data_info *rlc, enum CodingScheme cs, bool with_padding, unsigned int header_bits, const unsigned int spb) { unsigned int i; unsigned int padding_bits = with_padding ? mcs_opt_padding_bits(cs) : 0; rlc->cs = cs; rlc->r = 0; rlc->si = 0; rlc->tfi = 0; rlc->cps = 0; rlc->rsb = 0; rlc->usf = 0; rlc->es_p = 0; rlc->rrbp = 0; rlc->pr = 0; rlc->num_data_blocks = num_data_blocks(mcs_header_type(cs)); rlc->with_padding = with_padding; OSMO_ASSERT(rlc->num_data_blocks <= ARRAY_SIZE(rlc->block_info)); for (i = 0; i < rlc->num_data_blocks; i++) { gprs_rlc_data_block_info_init(&rlc->block_info[i], cs, with_padding, spb); rlc->data_offs_bits[i] = header_bits + padding_bits + (i+1) * num_data_block_header_bits(mcs_header_type(cs)) + i * 8 * rlc->block_info[0].data_len; } } void gprs_rlc_data_info_init_dl(struct gprs_rlc_data_info *rlc, enum CodingScheme cs, bool with_padding, const unsigned int spb) { OSMO_ASSERT(mcs_is_valid(cs)); return gprs_rlc_data_header_init(rlc, cs, with_padding, num_data_header_bits_DL(mcs_header_type(cs)), spb); } void gprs_rlc_data_info_init_ul(struct gprs_rlc_data_info *rlc, enum CodingScheme cs, bool with_padding) { OSMO_ASSERT(mcs_is_valid(cs)); /* * last parameter is sent as 0 since common function used * for both DL and UL */ return gprs_rlc_data_header_init(rlc, cs, with_padding, num_data_header_bits_UL(mcs_header_type(cs)), 0); } 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 data_len = mcs_max_data_block_bytes(cs); if (with_padding) data_len -= mcs_opt_padding_bits(cs) / 8; rdbi->data_len = data_len; rdbi->bsn = 0; rdbi->ti = 0; rdbi->e = 1; rdbi->cv = 15; rdbi->pi = 0; rdbi->spb = spb; } unsigned int gprs_rlc_mcs_cps(enum CodingScheme cs, enum egprs_puncturing_values punct, enum egprs_puncturing_values punct2, bool with_padding) { /* validate that punct and punct2 are as expected */ switch (cs) { case MCS9: case MCS8: case MCS7: if (punct2 == EGPRS_PS_INVALID) { LOGP(DRLCMACDL, LOGL_ERROR, "Invalid punct2 value for coding scheme %d: %d\n", cs, punct2); return -1; } /* fall through */ case MCS6: case MCS5: case MCS4: case MCS3: case MCS2: case MCS1: if (punct == EGPRS_PS_INVALID) { LOGP(DRLCMACDL, LOGL_ERROR, "Invalid punct value for coding scheme %d: %d\n", cs, punct); return -1; } break; default: return -1; } /* See 3GPP TS 44.060 10.4.8a.3.1, 10.4.8a.2.1, 10.4.8a.1.1 */ switch (cs) { case MCS1: return 0b1011 + punct % EGPRS_MAX_PS_NUM_2; case MCS2: return 0b1001 + punct % EGPRS_MAX_PS_NUM_2; case MCS3: return (with_padding ? 0b0110 : 0b0011) + punct % EGPRS_MAX_PS_NUM_3; case MCS4: return 0b0000 + punct % EGPRS_MAX_PS_NUM_3; case MCS5: return 0b100 + punct % EGPRS_MAX_PS_NUM_2; case MCS6: return (with_padding ? 0b010 : 0b000) + punct % EGPRS_MAX_PS_NUM_2; case MCS7: return 0b10100 + 3 * (punct % EGPRS_MAX_PS_NUM_3) + punct2 % EGPRS_MAX_PS_NUM_3; case MCS8: return 0b01011 + 3 * (punct % EGPRS_MAX_PS_NUM_3) + punct2 % EGPRS_MAX_PS_NUM_3; case MCS9: return 0b00000 + 4 * (punct % EGPRS_MAX_PS_NUM_3) + punct2 % EGPRS_MAX_PS_NUM_3; default: ; } return -1; } void gprs_rlc_mcs_cps_decode(unsigned int cps, enum CodingScheme cs, int *punct, int *punct2, int *with_padding) { *punct2 = -1; *with_padding = 0; switch (cs) { case MCS1: cps -= 0b1011; *punct = cps % 2; break; case MCS2: cps -= 0b1001; *punct = cps % 2; break; case MCS3: cps -= 0b0011; *punct = cps % 3; *with_padding = cps >= 3; break; case MCS4: cps -= 0b0000; *punct = cps % 3; break; case MCS5: cps -= 0b100; *punct = cps % 2; break; case MCS6: cps -= 0b000; *punct = cps % 2; *with_padding = cps >= 2; break; case MCS7: cps -= 0b10100; *punct = cps / 3; *punct2 = cps % 3; break; case MCS8: cps -= 0b01011; *punct = cps / 3; *punct2 = cps % 3; break; case MCS9: cps -= 0b00000; *punct = cps / 4; *punct2 = cps % 3; break; default: ; } } /* * Finds the PS value for retransmission with MCS change, * retransmission with no MCS change, fresh transmission cases. * The return value shall be used for current transmission only * 44.060 9.3.2.1 defines the PS selection for MCS change case * cs_current is the output of MCS selection algorithm for retx * cs is coding scheme of previous transmission of RLC data block */ enum egprs_puncturing_values gprs_get_punct_scheme( enum egprs_puncturing_values punct, const enum CodingScheme &cs, const enum CodingScheme &cs_current, const enum egprs_rlcmac_dl_spb spb) { /* * 10.4.8b of TS 44.060 * If it is second segment of the block * dont change the puncturing scheme */ if (spb == EGPRS_RLCMAC_DL_SEC_SEG) return punct; /* TS 44.060 9.3.2.1.1 */ if ((cs == MCS9) && (cs_current == MCS6)) { if ((punct == EGPRS_PS_1) || (punct == EGPRS_PS_3)) return EGPRS_PS_1; else if (punct == EGPRS_PS_2) return EGPRS_PS_2; } else if ((cs == MCS6) && (cs_current == MCS9)) { if (punct == EGPRS_PS_1) return EGPRS_PS_3; else if (punct == EGPRS_PS_2) return EGPRS_PS_2; } else if ((cs == MCS7) && (cs_current == MCS5)) return EGPRS_PS_1; else if ((cs == MCS5) && (cs_current == MCS7)) return EGPRS_PS_2; else if (cs != cs_current) return EGPRS_PS_1; /* TS 44.060 9.3.2.1.1 ends here */ /* * Below else will handle fresh transmission, retransmission with no * MCS change case */ else return punct; return EGPRS_PS_INVALID; } /* * This function calculates puncturing scheme for retransmission of a RLC * block with same MCS. The computed value shall be used for next transmission * of the same RLC block * TS 44.060 10.4.8a.3.1, 10.4.8a.2.1, 10.4.8a.1.1 */ void gprs_update_punct_scheme(enum egprs_puncturing_values *punct, const enum CodingScheme &cs) { switch (cs) { case MCS1 : case MCS2 : case MCS5 : case MCS6 : *punct = ((enum egprs_puncturing_values)((*punct + 1) % EGPRS_MAX_PS_NUM_2)); break; case MCS3 : case MCS4 : case MCS7 : case MCS8 : case MCS9 : *punct = ((enum egprs_puncturing_values)((*punct + 1) % EGPRS_MAX_PS_NUM_3)); break; default: break; } }