Velocidades 802.11n no BCM4313
Eu criou um ponto de acesso usando a seguinte configuração hostapd :
#####Basic Settings########################
#sets the wifi interface to use, is wlan0 in most cases
interface=wlan0
#driver to use, nl80211 works in most cases
driver=nl80211
#Access Point name
ssid=HEXspot
#####Channel and Mode Settings#############
# Operation mode (a = IEEE 802.11a, b = IEEE 802.11b, g = IEEE 802.11g,
# ad = IEEE 802.11ad (60 GHz); a/g options are used with IEEE 802.11n, too, to
# specify band)
# Default: IEEE 802.11b
hw_mode=g
# WiFi Channel:
channel=11
##### IEEE 802.11n related configuration ##
#WMM needs to be enabled for full HT functionality
wmm_enabled=1
# ieee80211n: Whether IEEE 802.11n (HT) is enabled
# 0 = disabled (default)
# 1 = enabled
# Note: You will also need to enable WMM for full HT functionality.
ieee80211n=1
# ht_capab: HT capabilities (list of flags)
# LDPC coding capability: [LDPC] = supported
# Supported channel width set: [HT40-] = both 20 MHz and 40 MHz with secondary
# channel below the primary channel; [HT40+] = both 20 MHz and 40 MHz
# with secondary channel below the primary channel
# (20 MHz only if neither is set)
# Note: There are limits on which channels can be used with HT40- and
# HT40+. Following table shows the channels that may be available for
# HT40- and HT40+ use per IEEE 802.11n Annex J:
# freq HT40- HT40+
# 2.4 GHz 5-13 1-7 (1-9 in Europe/Japan)
# 5 GHz 40,48,56,64 36,44,52,60
# (depending on the location, not all of these channels may be available
# for use)
# Please note that 40 MHz channels may switch their primary and secondary
# channels if needed or creation of 40 MHz channel maybe rejected based
# on overlapping BSSes. These changes are done automatically when hostapd
# is setting up the 40 MHz channel.
# Spatial Multiplexing (SM) Power Save: [SMPS-STATIC] or [SMPS-DYNAMIC]
# (SMPS disabled if neither is set)
# HT-greenfield: [GF] (disabled if not set)
# Short GI for 20 MHz: [SHORT-GI-20] (disabled if not set)
# Short GI for 40 MHz: [SHORT-GI-40] (disabled if not set)
# Tx STBC: [TX-STBC] (disabled if not set)
# Rx STBC: [RX-STBC1] (one spatial stream), [RX-STBC12] (one or two spatial
# streams), or [RX-STBC123] (one, two, or three spatial streams); Rx STBC
# disabled if none of these set
# HT-delayed Block Ack: [DELAYED-BA] (disabled if not set)
# Maximum A-MSDU length: [MAX-AMSDU-7935] for 7935 octets (3839 octets if not
# set)
# DSSS/CCK Mode in 40 MHz: [DSSS_CCK-40] = allowed (not allowed if not set)
# PSMP support: [PSMP] (disabled if not set)
# L-SIG TXOP protection support: [LSIG-TXOP-PROT] (disabled if not set)
ht_capab=[HT40][GF][SHORT-GI-40][SHORT-GI-20]
# Require stations to support HT PHY (reject association if they do not)
require_ht=1
#####Security and Authentication###########
#macaddr_acl sets options for mac address filtering. 0 means "accept unless in deny list"
macaddr_acl=0
#Sets authentication algorithm
#1 - only open system authentication
#2 - both open system authentication and shared key authentication
auth_algs=1
#setting ignore_broadcast_ssid to 1 will disable the broadcasting of ssid
ignore_broadcast_ssid=0
#####Sets WPA and WPA2 authentication######
#wpa option sets which wpa implementation to use
#1 - wpa only
#2 - wpa2 only
#3 - both
wpa=2
#sets WPA Password required by the clients to authenticate themselves on the network
wpa_passphrase=anything
#sets wpa key management
wpa_key_mgmt=WPA-PSK
#sets encryption used by WPA2
rsn_pairwise=CCMP
Meu sistema é o Ubuntu 12.04.4 com o kernel linux-generic-lts-saucy (o kernel 3.11 do Saucy é retornado para o Ubuntu 12.04LTS ). Eu usei o driver sem fio brcmsmac , que tem suporte ao modo AP do kernel 3.10 em diante. Consegui obter uma velocidade de link 802.11n de 72Mbps na banda de 2,4GHz com largura de canal de 20MHz. Mas, como no seu caso, a velocidade de transferência real é inferior a 1MBps, mesmo para transferências por FTP.
Como o BCM4313 não pode operar em 5GHz, não podemos obter velocidades de n modo de ligação de canal de qualquer maneira. Nossa melhor aposta é obter largura do canal de 40MHz (modo HT40) na banda de 2,4GHz. O problema é que brcmsmac não suporta adequadamente o modo 40MHz na banda de 2.4GHz, pelo menos para o BCM4313. Não há suporte para o modo DSSS / CCK. Espero que o driver melhore nos novos kernels. Quando o Ubuntu 14.04 Trusty Tahr for lançado, tentarei novamente com seu kernel 3.13.