This patch includes the changes for encoding of PUAN to handle the CRBB bitmap --- src/encoding.cpp | 103 ++++++++++++++++++++++++++++++++++++++++++------------ src/rlc.cpp | 28 +++++++++++++++ src/rlc.h | 1 + 3 files changed, 109 insertions(+), 23 deletions(-) diff --git a/src/encoding.cpp b/src/encoding.cpp index 6c50abe..e0c29af 100644 --- a/src/encoding.cpp +++ b/src/encoding.cpp @@ -25,6 +25,11 @@ #include <tbf.h> #include <gprs_debug.h> +extern "C" { +#include <osmocom/core/utils.h> +#include <osmocom/core/bitcomp.h> +} + #include <errno.h> #include <string.h> @@ -537,8 +542,6 @@ static void write_packet_ack_nack_desc_egprs( gprs_rlc_ul_window *window, bool is_final) { int urbb_len = 0; - int crbb_len = 0; - int len; bool bow = true; bool eow = true; int ssn = window->mod_sns(window->v_q() + 1); @@ -546,9 +549,55 @@ static void write_packet_ack_nack_desc_egprs( int esn_crbb = window->mod_sns(ssn - 1); int rest_bits = dest->data_len * 8 - wp; - if (num_blocks > 0) + uint8_t rbb[128] = {'\0'}; + uint8_t iter = 0; + uint8_t crbb_len = 0; + uint8_t len = 0; + int is_compressed = 0; + uint16_t ucmp_bmplan = window->update_egprs_rbb(rbb); + uint8_t crbb_bitmap[127]; + bool bitmap_len = 0; + + LOGP(DRLCMACUL, LOGL_DEBUG, "Uncompressed bitmap length after" + "rbb update %d\n", ucmp_bmplan); + + rbb[128] = 0; + bitvec out; + + out.data = rbb; + out.cur_bit = 0; + out.data_len = sizeof(rbb); + /* if [V(R) -1] modulo SNS is explicitly included in the bitmap, + set eow =1; + + * If V(Q) equals V(R), then BOW and EOW bit shall be set to the value '1' + * and no need to send bitmap in ack nack, hence no compression + */ + if (window->v_q() == window->v_r()) { + + LOGP(DRLCMACUL, LOGL_DEBUG, "write_packet_ack_nack_desc_egprs:" + "v(Q)=V(R), hence no compression" + " %d %d\n", window->v_q(), window->v_r()); + eow = bow = 1; + bitmap_len = 1; + } + /* Compression part, Try compression only if it is greater than or equal + * to Window size Otherwise encode it in uncompressed + */ + if ((ucmp_bmplan >= (rest_bits - 15)) && (!bitmap_len)) { + + is_compressed = osmo_bitmap_compress(&out, //Uncompressed bitmap + &ucmp_bmplan, //Uncompressed bitmap len + &crbb_len, //Compressed bitmap len + crbb_bitmap + ); + } + + if (num_blocks > 0) { /* V(Q) is NACK and omitted -> SSN = V(Q) + 1 */ num_blocks -= 1; + urbb_len = num_blocks; + } if (num_blocks > window->ws()) num_blocks = window->ws(); @@ -556,17 +605,10 @@ static void write_packet_ack_nack_desc_egprs( if (num_blocks > rest_bits) { eow = false; urbb_len = rest_bits; - /* TODO: use compression, start encoding bits and stop when the - * space is exhausted. Use the first combination that encodes - * all bits. If there is none, use the combination that encodes - * the largest number of bits (e.g. by setting num_blocks to the - * max and repeating the construction). - */ } else if (num_blocks > rest_bits - 9) { /* union bit and length field take 9 bits */ eow = false; urbb_len = rest_bits - 9; - /* TODO: use compression (see above) */ } if (urbb_len + crbb_len == rest_bits) @@ -588,20 +630,35 @@ static void write_packet_ack_nack_desc_egprs( bitvec_write_field(dest, wp, bow, 1); // BEGINNING_OF_WINDOW bitvec_write_field(dest, wp, eow, 1); // END_OF_WINDOW bitvec_write_field(dest, wp, ssn, 11); // STARTING_SEQUENCE_NUMBER - bitvec_write_field(dest, wp, 0, 1); // 0: don't have CRBB - /* TODO: Add CRBB support */ - - LOGP(DRLCMACUL, LOGL_DEBUG, - " - EGPRS URBB, len = %d, SSN = %d, ESN_CRBB = %d, " - "SNS = %d, WS = %d, V(Q) = %d, V(R) = %d%s%s\n", - urbb_len, ssn, esn_crbb, - window->sns(), window->ws(), window->v_q(), window->v_r(), - bow ? ", BOW" : "", eow ? ", EOW" : ""); - for (int i = urbb_len; i > 0; i--) { - /* Set bit at the appropriate position (see 3GPP TS 04.60 12.3.1) */ - bool is_ack = window->m_v_n.is_received(esn_crbb + i); - bitvec_write_field(dest, wp, is_ack, 1); + if (is_compressed) { + bitvec_write_field(dest, wp, 1, 1); // CRBB_Exist + bitvec_write_field(dest, wp, crbb_len, 7); // CRBB_LENGTH + uint8_t crbb_start_clr_code = (0x80 & crbb_bitmap[0])>>7; + bitvec_write_field(dest, wp, crbb_start_clr_code, 1); // CRBB_clr_code + + while (crbb_len != 0) { + if (crbb_len > 8) { + bitvec_write_field(dest, wp, crbb_bitmap[iter], 8); + crbb_len = crbb_len - 8; + iter++; + } else{ + bitvec_write_field(dest, wp, crbb_bitmap[iter], crbb_len); + crbb_len = 0; + } + } + } else{ + LOGP(DRLCMACUL, LOGL_DEBUG, + " - EGPRS URBB, len = %d, SSN = %d, ESN_CRBB = %d, " + "SNS = %d, WS = %d, V(Q) = %d, V(R) = %d%s%s\n", + urbb_len, ssn, esn_crbb, + window->sns(), window->ws(), window->v_q(), window->v_r(), + bow ? ", BOW" : "", eow ? ", EOW" : ""); + for (int i = urbb_len; i > 0; i--) { + /* Set bit at the appropriate position (see 3GPP TS 04.60 12.3.1) */ + bool is_ack = window->m_v_n.is_received(esn_crbb + i); + bitvec_write_field(dest, wp, is_ack, 1); + } } } diff --git a/src/rlc.cpp b/src/rlc.cpp index 6770043..c201713 100644 --- a/src/rlc.cpp +++ b/src/rlc.cpp @@ -83,6 +83,34 @@ int gprs_rlc_dl_window::mark_for_resend() return resend; } +/* Update the receive block bitmap */ +uint16_t gprs_rlc_ul_window::update_egprs_rbb(uint8_t *rbb) +{ + int i; + uint16_t bsn; + int8_t bitmask = 0x80; + int8_t pos = 0; + int8_t bit_pos = 0; + for (i = 0, bsn = (v_q()+1); ((bsn < (v_r())) && (i < ws())); i++, + bsn = this->mod_sns(bsn + 1)) { + if (m_v_n.is_received(bsn)) { + rbb[pos] = rbb[pos] | bitmask; + } else { + rbb[pos] = rbb[pos] & (~bitmask); + } + bitmask = bitmask >> 1; + bit_pos++; + bit_pos = bit_pos % 8; + if(bit_pos == 0) { + pos++; + bitmask = 0x80; + } + } + LOGP(DRLCMACUL, LOGL_DEBUG, "V(N):in update_egprs_rbb \"%s\"" + "R=Received I=Invalid\n", rbb); + return i; +} + int gprs_rlc_dl_window::count_unacked() { uint16_t unacked = 0; diff --git a/src/rlc.h b/src/rlc.h index 8f75588..83bc5dc 100644 --- a/src/rlc.h +++ b/src/rlc.h @@ -260,6 +260,7 @@ struct gprs_rlc_ul_window: public gprs_rlc_window { 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(); -- 1.7.9.5