| /* gprs_coding_scheme.cpp |
| * |
| * Copyright (C) 2015 by Sysmocom s.f.m.c. GmbH |
| * Author: Jacob Erlbeck <jerlbeck@sysmocom.de> |
| * |
| * 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. |
| */ |
| |
| |
| #include "gprs_coding_scheme.h" |
| |
| enum Family { |
| FAMILY_INVALID, |
| FAMILY_A, |
| FAMILY_B, |
| FAMILY_C, |
| }; |
| |
| static struct { |
| struct { |
| uint8_t bytes; |
| uint8_t ext_bits; |
| uint8_t data_header_bits; |
| } uplink, downlink; |
| uint8_t data_bytes; |
| uint8_t optional_padding_bits; |
| enum HeaderType data_hdr; |
| enum Family family; |
| } mcs_info[NUM_SCHEMES] = { |
| {{0, 0}, {0, 0}, 0, 0, |
| HEADER_INVALID, FAMILY_INVALID}, |
| {{23, 0}, {23, 0}, 20, 0, |
| HEADER_GPRS_DATA, FAMILY_INVALID}, |
| {{33, 7}, {33, 7}, 30, 0, |
| HEADER_GPRS_DATA, FAMILY_INVALID}, |
| {{39, 3}, {39, 3}, 36, 0, |
| HEADER_GPRS_DATA, FAMILY_INVALID}, |
| {{53, 7}, {53, 7}, 50, 0, |
| HEADER_GPRS_DATA, FAMILY_INVALID}, |
| |
| {{26, 1}, {26, 1}, 22, 0, |
| HEADER_EGPRS_DATA_TYPE_3, FAMILY_C}, |
| {{32, 1}, {32, 1}, 28, 0, |
| HEADER_EGPRS_DATA_TYPE_3, FAMILY_B}, |
| {{41, 1}, {41, 1}, 37, 48, |
| HEADER_EGPRS_DATA_TYPE_3, FAMILY_A}, |
| {{48, 1}, {48, 1}, 44, 0, |
| HEADER_EGPRS_DATA_TYPE_3, FAMILY_C}, |
| |
| {{60, 7}, {59, 6}, 56, 0, |
| HEADER_EGPRS_DATA_TYPE_2, FAMILY_B}, |
| {{78, 7}, {77, 6}, 74, 48, |
| HEADER_EGPRS_DATA_TYPE_2, FAMILY_A}, |
| {{118, 2}, {117, 4}, 56, 0, |
| HEADER_EGPRS_DATA_TYPE_1, FAMILY_B}, |
| {{142, 2}, {141, 4}, 68, 0, |
| HEADER_EGPRS_DATA_TYPE_1, FAMILY_A}, |
| {{154, 2}, {153, 4}, 74, 0, |
| HEADER_EGPRS_DATA_TYPE_1, FAMILY_A}, |
| }; |
| |
| GprsCodingScheme GprsCodingScheme::getBySizeUL(unsigned size) |
| { |
| switch (size) { |
| case 23: return GprsCodingScheme(CS1); |
| case 27: return GprsCodingScheme(MCS1); |
| case 33: return GprsCodingScheme(MCS2); |
| case 34: return GprsCodingScheme(CS2); |
| case 40: return GprsCodingScheme(CS3); |
| case 42: return GprsCodingScheme(MCS3); |
| case 49: return GprsCodingScheme(MCS4); |
| case 54: return GprsCodingScheme(CS4); |
| case 61: return GprsCodingScheme(MCS5); |
| case 79: return GprsCodingScheme(MCS6); |
| case 119: return GprsCodingScheme(MCS7); |
| case 143: return GprsCodingScheme(MCS8); |
| case 155: return GprsCodingScheme(MCS9); |
| } |
| |
| return GprsCodingScheme(UNKNOWN); |
| } |
| |
| uint8_t GprsCodingScheme::sizeUL() const |
| { |
| return mcs_info[m_scheme].uplink.bytes + (spareBitsUL() ? 1 : 0); |
| } |
| |
| uint8_t GprsCodingScheme::usedSizeUL() const |
| { |
| if (mcs_info[m_scheme].data_hdr == HEADER_GPRS_DATA) |
| return mcs_info[m_scheme].uplink.bytes; |
| else |
| return sizeUL(); |
| } |
| |
| uint8_t GprsCodingScheme::maxBytesUL() const |
| { |
| return mcs_info[m_scheme].uplink.bytes; |
| } |
| |
| uint8_t GprsCodingScheme::spareBitsUL() const |
| { |
| return mcs_info[m_scheme].uplink.ext_bits; |
| } |
| |
| uint8_t GprsCodingScheme::sizeDL() const |
| { |
| return mcs_info[m_scheme].downlink.bytes + (spareBitsDL() ? 1 : 0); |
| } |
| |
| uint8_t GprsCodingScheme::usedSizeDL() const |
| { |
| if (mcs_info[m_scheme].data_hdr == HEADER_GPRS_DATA) |
| return mcs_info[m_scheme].downlink.bytes; |
| else |
| return sizeDL(); |
| } |
| |
| uint8_t GprsCodingScheme::maxBytesDL() const |
| { |
| return mcs_info[m_scheme].downlink.bytes; |
| } |
| |
| uint8_t GprsCodingScheme::spareBitsDL() const |
| { |
| return mcs_info[m_scheme].downlink.ext_bits; |
| } |
| |
| uint8_t GprsCodingScheme::maxDataBlockBytes() const |
| { |
| return mcs_info[m_scheme].data_bytes; |
| } |
| |
| uint8_t GprsCodingScheme::optionalPaddingBits() const |
| { |
| return mcs_info[m_scheme].optional_padding_bits; |
| } |
| |
| enum HeaderType GprsCodingScheme::headerTypeData() const |
| { |
| return mcs_info[m_scheme].data_hdr; |
| } |
| |
| void GprsCodingScheme::inc(enum mcs_kind mode) |
| { |
| if (!isCompatible(mode)) |
| /* This should not happen. TODO: Use assert? */ |
| return; |
| |
| CodingScheme new_cs(CodingScheme(m_scheme + 1)); |
| if (!GprsCodingScheme(new_cs).isCompatible(mode)) |
| /* Clipping, do not change the value */ |
| return; |
| |
| m_scheme = new_cs; |
| } |
| |
| void GprsCodingScheme::dec(enum mcs_kind mode) |
| { |
| if (!isCompatible(mode)) |
| /* This should not happen. TODO: Use assert? */ |
| return; |
| |
| CodingScheme new_cs(CodingScheme(m_scheme - 1)); |
| if (!GprsCodingScheme(new_cs).isCompatible(mode)) |
| /* Clipping, do not change the value */ |
| return; |
| |
| m_scheme = new_cs; |
| } |
| |
| void GprsCodingScheme::inc() |
| { |
| if (mcs_is_gprs(m_scheme) && m_scheme == CS4) |
| return; |
| |
| if (mcs_is_edge(m_scheme) && m_scheme == MCS9) |
| return; |
| |
| if (!isValid()) |
| return; |
| |
| m_scheme = CodingScheme(m_scheme + 1); |
| } |
| |
| void GprsCodingScheme::dec() |
| { |
| if (mcs_is_gprs(m_scheme) && m_scheme == CS1) |
| return; |
| |
| if (mcs_is_edge(m_scheme) && m_scheme == MCS1) |
| return; |
| |
| if (!isValid()) |
| return; |
| |
| m_scheme = CodingScheme(m_scheme - 1); |
| } |
| |
| bool GprsCodingScheme::isFamilyCompatible(GprsCodingScheme o) const |
| { |
| if (*this == o) |
| return true; |
| |
| if (mcs_info[m_scheme].family == FAMILY_INVALID) |
| return false; |
| |
| return mcs_info[m_scheme].family == mcs_info[o.m_scheme].family; |
| } |
| |
| void GprsCodingScheme::decToSingleBlock(bool *needStuffing) |
| { |
| switch (m_scheme) { |
| case MCS7: *needStuffing = false; m_scheme = MCS5; break; |
| case MCS8: *needStuffing = true; m_scheme = MCS6; break; |
| case MCS9: *needStuffing = false; m_scheme = MCS6; break; |
| default: *needStuffing = false; break; |
| } |
| } |