MadWifi理解笔记091208(rate/rix)

最新推荐文章于 2021-05-12 12:28:10 发布

原创最新推荐文章于 2021-05-12 12:28:10 发布 · 1.2k 阅读

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本文详细解析了无线网络中速率配置的过程，包括如何通过不同结构体定义和计算速率，展示了速率映射表的构建方法及速率的具体计算公式。

sn->num_rates = ni->ni_rates.rs_nrates; for (x = 0; x < ni->ni_rates.rs_nrates; x++) { sn->rates[x].rate = ni->ni_rates.rs_rates[x] & IEEE80211_RATE_VAL; sn->rates[x].rix = sc->sc_rixmap[sn->rates[x].rate]; if (sn->rates[x].rix == 0xff) { DPRINTF(sc, ATH_DEBUG_RATE, "%s: %s ignore bogus rix at %u/n", dev_info, __func__, x); continue; } sn->rates[x].rateCode = rt->info[sn->rates[x].rix].rateCode; sn->rates[x].shortPreambleRateCode = rt->info[sn->rates[x].rix].rateCode | rt->info[sn->rates[x].rix].shortPreamble; }

ni->ni_rates.rs_nrate=12;

ni->ni_rates.rs_rates[x]={130,132,139,12,18,150,24,36,48,72,96,108};

所以(-128)

sn->rates[x].rate = {2,4,11,12,18,22,24,36,48,72,96,108};

分别对应速率

{1 2 5.5 6 9 11 12 18 24 36 48 54} Mbps

sn->rates[x].rix = {0 1 2 4 5 3 6 7 8 9 10 11}

sn->rates[x].rateCode = {27 26 25 11 15 24 10 14 9 13 8 12};

#define AR5K_MAX_RATES 32 typedef struct { u_int8_t valid; u_int8_t phy; u_int16_t rateKbps; u_int8_t rateCode; u_int8_t shortPreamble; u_int8_t dot11Rate; u_int8_t controlRate; u_int8_t spAckDuration; /* XXX */ u_int8_t lpAckDuration; /* XXX */ #define r_valid valid #define r_phy phy #define r_rate_kbps rateKbps #define r_rate_code rateCode #define r_short_preamble shortPreamble #define r_dot11_rate dot11Rate #define r_control_rate controlRate } HAL_RATE; typedef struct { u_int16_t rateCount; u_int8_t rateCodeToIndex[AR5K_MAX_RATES]; HAL_RATE info[AR5K_MAX_RATES]; #define rt_rate_count rateCount #define rt_rate_code_index rateCodeToIndex #define rt_info info } HAL_RATE_TABLE;

#define AR5K_RATES_11G { 12, { / 255, 255, 255, 255, 255, 255, 255, 255, 10, 8, 6, 4, / 11, 9, 7, 5, 255, 255, 255, 255, 255, 255, 255, 255, / 3, 2, 1, 0, 255, 255, 255, 255 }, { / { 1, IEEE80211_T_CCK, 1000, 27, 0x00, 2, 0 }, / { 1, IEEE80211_T_CCK, 2000, 26, 0x04, 4, 1 }, / { 1, IEEE80211_T_CCK, 5500, 25, 0x04, 11, 1 }, / { 1, IEEE80211_T_CCK, 11000, 24, 0x04, 22, 1 }, / { 0, IEEE80211_T_OFDM, 6000, 11, 0, 12, 4 }, / { 0, IEEE80211_T_OFDM, 9000, 15, 0, 18, 4 }, / { 1, IEEE80211_T_OFDM, 12000, 10, 0, 24, 6 }, / { 1, IEEE80211_T_OFDM, 18000, 14, 0, 36, 6 }, / { 1, IEEE80211_T_OFDM, 24000, 9, 0, 48, 8 }, / { 1, IEEE80211_T_OFDM, 36000, 13, 0, 72, 8 }, / { 1, IEEE80211_T_OFDM, 48000, 8, 0, 96, 8 }, / { 1, IEEE80211_T_OFDM, 54000, 12, 0, 108, 8 } } / }