/* rlc header descriptions * * Copyright (C) 2012 Ivan Klyuchnikov * Copyright (C) 2012 Andreas Eversberg * * 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. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ #pragma once #include "gprs_coding_scheme.h" #include #include #define RLC_GPRS_SNS 128 /* GPRS, must be power of 2 */ #define RLC_GPRS_WS 64 /* max window size */ #define RLC_EGPRS_MIN_WS 64 /* min window size */ #define RLC_EGPRS_MAX_WS 1024 /* min window size */ #define RLC_EGPRS_SNS 2048 /* EGPRS, must be power of 2 */ #define RLC_EGPRS_MAX_BSN_DELTA 512 #define RLC_MAX_SNS RLC_EGPRS_SNS #define RLC_MAX_WS RLC_EGPRS_MAX_WS #define RLC_MAX_LEN 74 /* MCS-9 data unit */ struct BTS; struct gprs_rlc_v_n; /* The state of a BSN in the send/receive window */ enum gprs_rlc_ul_bsn_state { GPRS_RLC_UL_BSN_INVALID, GPRS_RLC_UL_BSN_RECEIVED, GPRS_RLC_UL_BSN_MISSING, GPRS_RLC_UL_BSN_MAX, }; enum gprs_rlc_dl_bsn_state { GPRS_RLC_DL_BSN_INVALID, GPRS_RLC_DL_BSN_NACKED, GPRS_RLC_DL_BSN_ACKED, GPRS_RLC_DL_BSN_UNACKED, GPRS_RLC_DL_BSN_RESEND, GPRS_RLC_DL_BSN_MAX, }; /* * 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 { GprsCodingScheme 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; unsigned int num_data_blocks; 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 { uint8_t *prepare(size_t block_data_length); void put_data(const uint8_t *data, size_t len); /* 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. */ GprsCodingScheme cs_current_trans; GprsCodingScheme cs_last; /* * The MCS of initial transmission of a BSN * This variable is used for split block * processing in DL */ GprsCodingScheme 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; }; void gprs_rlc_data_info_init_dl(struct gprs_rlc_data_info *rlc, GprsCodingScheme cs, bool with_padding, const unsigned int spb); void gprs_rlc_data_info_init_ul(struct gprs_rlc_data_info *rlc, GprsCodingScheme cs, bool with_padding); void gprs_rlc_data_block_info_init(struct gprs_rlc_data_block_info *rdbi, GprsCodingScheme cs, bool with_padding, const unsigned int spb); unsigned int gprs_rlc_mcs_cps(GprsCodingScheme cs, enum egprs_puncturing_values punct, enum egprs_puncturing_values punct2, int with_padding); void gprs_rlc_mcs_cps_decode(unsigned int cps, GprsCodingScheme cs, int *punct, int *punct2, int *with_padding); enum egprs_puncturing_values gprs_get_punct_scheme(enum egprs_puncturing_values punct, const GprsCodingScheme &cs, const GprsCodingScheme &cs_current_trans, const enum egprs_rlcmac_dl_spb spb); void gprs_update_punct_scheme(enum egprs_puncturing_values *punct, const GprsCodingScheme &cs); /* * I hold the currently transferred blocks and will provide * the routines to manipulate these arrays. */ struct gprs_rlc { gprs_rlc_data *block(int bsn); gprs_rlc_data m_blocks[RLC_MAX_SNS/2]; }; /** * TODO: for GPRS/EDGE maybe make sns a template parameter * so we create specialized versions... */ struct gprs_rlc_v_b { /* Check for an individual frame */ bool is_unacked(int bsn) const; bool is_nacked(int bsn) const; bool is_acked(int bsn) const; bool is_resend(int bsn) const; bool is_invalid(int bsn) const; gprs_rlc_dl_bsn_state get_state(int bsn) const; /* Mark a RLC frame for something */ void mark_unacked(int bsn); void mark_nacked(int bsn); void mark_acked(int bsn); void mark_resend(int bsn); void mark_invalid(int bsn); void reset(); private: bool is_state(int bsn, const gprs_rlc_dl_bsn_state state) const; void mark(int bsn, const gprs_rlc_dl_bsn_state state); gprs_rlc_dl_bsn_state m_v_b[RLC_MAX_SNS/2]; /* acknowledge state array */ }; /** * TODO: The UL/DL code could/should share a base class. */ class gprs_rlc_window { public: gprs_rlc_window(); const uint16_t mod_sns() const; const uint16_t mod_sns(uint16_t bsn) const; const uint16_t sns() const; const uint16_t ws() const; void set_sns(uint16_t sns); void set_ws(uint16_t ws); protected: uint16_t m_sns; uint16_t m_ws; }; struct gprs_rlc_dl_window: public gprs_rlc_window { void reset(); bool window_stalled() const; bool window_empty() const; void increment_send(); void raise(int moves); const uint16_t v_s() const; const uint16_t v_s_mod(int offset) const; const uint16_t v_a() const; const uint16_t distance() const; /* Methods to manage reception */ int resend_needed(); int mark_for_resend(); void update(BTS *bts, char *show_rbb, uint16_t ssn, uint16_t *lost, uint16_t *received); void update(BTS *bts, const struct bitvec *rbb, uint16_t first_bsn, uint16_t *lost, uint16_t *received); int move_window(); void show_state(char *show_rbb); int count_unacked(); uint16_t m_v_s; /* send state */ uint16_t m_v_a; /* ack state */ gprs_rlc_v_b m_v_b; gprs_rlc_dl_window(); }; struct gprs_rlc_v_n { void reset(); void mark_received(int bsn); void mark_missing(int bsn); bool is_received(int bsn) const; gprs_rlc_ul_bsn_state state(int bsn) const; private: bool is_state(int bsn, const gprs_rlc_ul_bsn_state state) const; void mark(int bsn, const gprs_rlc_ul_bsn_state state); gprs_rlc_ul_bsn_state m_v_n[RLC_MAX_SNS/2]; /* receive state array */ }; struct gprs_rlc_ul_window: public gprs_rlc_window { const uint16_t v_r() const; const uint16_t v_q() const; const void set_v_r(int); const void set_v_q(int); const uint16_t ssn() const; bool is_in_window(uint16_t bsn) const; bool is_received(uint16_t bsn) const; void update_rbb(char *rbb); uint16_t update_egprs_rbb(uint8_t *rbb); void raise_v_r_to(int moves); void raise_v_r(const uint16_t bsn); uint16_t raise_v_q(); void raise_v_q(int); void receive_bsn(const uint16_t bsn); bool invalidate_bsn(const uint16_t bsn); uint16_t m_v_r; /* receive state */ uint16_t m_v_q; /* receive window state */ gprs_rlc_v_n m_v_n; gprs_rlc_ul_window(); }; extern "C" { /* TS 04.60 10.2.2 */ #if OSMO_IS_LITTLE_ENDIAN struct rlc_ul_header { 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; } __attribute__ ((packed)); struct rlc_dl_header { 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; } __attribute__ ((packed)); struct rlc_li_field { uint8_t e:1, m:1, li:6; } __attribute__ ((packed)); struct rlc_li_field_egprs { uint8_t e:1, li:7; } __attribute__ ((packed)); #else # error "Only little endian headers are supported yet. TODO: add missing structs" #endif } inline bool gprs_rlc_v_b::is_state(int bsn, const gprs_rlc_dl_bsn_state type) const { return m_v_b[bsn & mod_sns_half()] == type; } inline void gprs_rlc_v_b::mark(int bsn, const gprs_rlc_dl_bsn_state type) { m_v_b[bsn & mod_sns_half()] = type; } inline bool gprs_rlc_v_b::is_nacked(int bsn) const { return is_state(bsn, GPRS_RLC_DL_BSN_NACKED); } inline bool gprs_rlc_v_b::is_acked(int bsn) const { return is_state(bsn, GPRS_RLC_DL_BSN_ACKED); } inline bool gprs_rlc_v_b::is_unacked(int bsn) const { return is_state(bsn, GPRS_RLC_DL_BSN_UNACKED); } inline bool gprs_rlc_v_b::is_resend(int bsn) const { return is_state(bsn, GPRS_RLC_DL_BSN_RESEND); } inline bool gprs_rlc_v_b::is_invalid(int bsn) const { return is_state(bsn, GPRS_RLC_DL_BSN_INVALID); } inline gprs_rlc_dl_bsn_state gprs_rlc_v_b::get_state(int bsn) const { return m_v_b[bsn & mod_sns_half()]; } inline void gprs_rlc_v_b::mark_resend(int bsn) { return mark(bsn, GPRS_RLC_DL_BSN_RESEND); } inline void gprs_rlc_v_b::mark_unacked(int bsn) { return mark(bsn, GPRS_RLC_DL_BSN_UNACKED); } inline void gprs_rlc_v_b::mark_acked(int bsn) { return mark(bsn, GPRS_RLC_DL_BSN_ACKED); } inline void gprs_rlc_v_b::mark_nacked(int bsn) { return mark(bsn, GPRS_RLC_DL_BSN_NACKED); } inline void gprs_rlc_v_b::mark_invalid(int bsn) { return mark(bsn, GPRS_RLC_DL_BSN_INVALID); } inline gprs_rlc_window::gprs_rlc_window() : m_sns(RLC_GPRS_SNS) , m_ws(RLC_GPRS_WS) { } inline const uint16_t gprs_rlc_window::sns() const { return m_sns; } inline const uint16_t gprs_rlc_window::ws() const { return m_ws; } inline const uint16_t gprs_rlc_window::mod_sns() const { return sns() - 1; } inline const uint16_t gprs_rlc_window::mod_sns(uint16_t bsn) const { return bsn & mod_sns(); } inline gprs_rlc_dl_window::gprs_rlc_dl_window() : m_v_s(0) , m_v_a(0) { } inline const uint16_t gprs_rlc_dl_window::v_s() const { return m_v_s; } inline const uint16_t gprs_rlc_dl_window::v_s_mod(int offset) const { return mod_sns(m_v_s + offset); } inline const uint16_t gprs_rlc_dl_window::v_a() const { return m_v_a; } inline bool gprs_rlc_dl_window::window_stalled() const { return (mod_sns(m_v_s - m_v_a)) == ws(); } inline bool gprs_rlc_dl_window::window_empty() const { return m_v_s == m_v_a; } inline void gprs_rlc_dl_window::increment_send() { m_v_s = (m_v_s + 1) & mod_sns(); } inline void gprs_rlc_dl_window::raise(int moves) { m_v_a = (m_v_a + moves) & mod_sns(); } inline const uint16_t gprs_rlc_dl_window::distance() const { return (m_v_s - m_v_a) & mod_sns(); } inline gprs_rlc_ul_window::gprs_rlc_ul_window() : m_v_r(0) , m_v_q(0) { } inline bool gprs_rlc_ul_window::is_in_window(uint16_t bsn) const { uint16_t offset_v_q; /* current block relative to lowest unreceived block */ offset_v_q = (bsn - m_v_q) & mod_sns(); /* If out of window (may happen if blocks below V(Q) are received * again. */ return offset_v_q < ws(); } inline bool gprs_rlc_ul_window::is_received(uint16_t bsn) const { uint16_t offset_v_r; /* Offset to the end of the received window */ offset_v_r = (m_v_r - 1 - bsn) & mod_sns(); return is_in_window(bsn) && m_v_n.is_received(bsn) && offset_v_r < ws(); } inline const void gprs_rlc_ul_window::set_v_r(int v_r) { m_v_r = v_r; } inline const void gprs_rlc_ul_window::set_v_q(int v_q) { m_v_q = v_q; } inline const uint16_t gprs_rlc_ul_window::v_r() const { return m_v_r; } inline const uint16_t gprs_rlc_ul_window::v_q() const { return m_v_q; } inline const uint16_t gprs_rlc_ul_window::ssn() const { return m_v_r; } inline void gprs_rlc_ul_window::raise_v_r_to(int moves) { m_v_r = mod_sns(m_v_r + moves); } inline void gprs_rlc_ul_window::raise_v_q(int incr) { m_v_q = mod_sns(m_v_q + incr); } inline void gprs_rlc_v_n::mark_received(int bsn) { return mark(bsn, GPRS_RLC_UL_BSN_RECEIVED); } inline void gprs_rlc_v_n::mark_missing(int bsn) { return mark(bsn, GPRS_RLC_UL_BSN_MISSING); } inline bool gprs_rlc_v_n::is_received(int bsn) const { return is_state(bsn, GPRS_RLC_UL_BSN_RECEIVED); } inline bool gprs_rlc_v_n::is_state(int bsn, gprs_rlc_ul_bsn_state type) const { return m_v_n[bsn & mod_sns_half()] == type; } inline void gprs_rlc_v_n::mark(int bsn, gprs_rlc_ul_bsn_state type) { m_v_n[bsn & mod_sns_half()] = type; } inline gprs_rlc_ul_bsn_state gprs_rlc_v_n::state(int bsn) const { return m_v_n[bsn & mod_sns_half()]; } inline gprs_rlc_data *gprs_rlc::block(int bsn) { return &m_blocks[bsn & mod_sns_half()]; }