barker preamble bit in ERP IE

ronit fichman ronit.fichman
Wed May 5 05:19:20 PDT 2010


hi

as write in the standart

When there are no NonERP STAs associated with the BSS and the ERP
Information Element sender.s

dot11ShortPreambleOptionImplemented MIB variable is set to true, then the
Barker_Preamble_Mode bit

may be set to 0. *The Barker_Preamble_Mode bit shall be set to 1 by the ERP
Information Element sender if*

*one or more associated NonERP STAs are not short preamble capable as
indicated in their Capability Information*

*field, or if the ERP Information Element senders
dot11ShortPreambleOptionImplemented MIB*

*variable is set to false*



in beacon.c :

static u8 ieee802_11_erp_info(struct hostapd_data *hapd)
{
 u8 erp = 0;

 if (hapd->iface->current_mode == NULL ||
     hapd->iface->current_mode->mode != HOSTAPD_MODE_IEEE80211G)
  return 0;

 switch (hapd->iconf->cts_protection_type) {
 case CTS_PROTECTION_FORCE_ENABLED:
  erp |= ERP_INFO_NON_ERP_PRESENT | ERP_INFO_USE_PROTECTION;
  break;
 case CTS_PROTECTION_FORCE_DISABLED:
  erp = 0;
  break;
 case CTS_PROTECTION_AUTOMATIC:
  if (hapd->iface->olbc)
   erp |= ERP_INFO_USE_PROTECTION;
  /* continue */
 case CTS_PROTECTION_AUTOMATIC_NO_OLBC:
  if (hapd->iface->num_sta_non_erp > 0) {
   erp |= ERP_INFO_NON_ERP_PRESENT |
    ERP_INFO_USE_PROTECTION;
  }
  break;
 }
* if (hapd->iface->num_sta_no_short_preamble > 0)
  erp |= ERP_INFO_BARKER_PREAMBLE_MODE;*

 return erp;
}

don't we need to sign barker bit also is th hostapd configure to long
preamble ?

if not the hostapd set this bit just in case not short preamble station is
associated



thank

Ronit
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.shmoo.com/pipermail/hostap/attachments/20100505/54b569f7/attachment-0001.htm 



More information about the Hostap mailing list