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CC3235MODS: auto connection policy

Part Number: CC3235MODS

Hi, 

Can you give me some information about the connection policy: 

SL_WLAN_CONNECTION_POLICY(1,0,0,0)

One of our customers has a lot of access points to the network and we would like to know how the module determines which access point it will use in the auto policy? It seems that they have observed modules that have connected to an access point far away while they wer under a other access point. 

What is for you the best connection method for this case: 

- Many access points to define the same network in a factory
- Embedded modules in a product that is relatively static after connection, but can be started anywhere in the factory 

Sincerly, 

Maxime L

  • Regarding the connection policy (see details in chapter 4.3.3.1 in the programmer's guide) - the decision is based on profile priority, security type of the AP and then the RSSI.

    Not sure i understand the 2nd part. Are you asking about AP role done by the simplelink or how he factory network needs to be organized? 

  • Hi Kobi,

    I think our problem may be with the scan. We are in an Auto policy configuration with the scan in this mode:

    ucConfigOpt = SL_WLAN_SCAN_POLICY(0, 0);
    ret = sl_WlanPolicySet(SL_WLAN_POLICY_SCAN, ucConfigOpt, NULL, 0);

    What happens when the auto connect mode is started? Is the scan performed 1 time on every frequency band? 

     For the second part, it is the same subject. I would like to know how to best configure our module (in Station mode) knowing that it has to connect in an environment with many AP available(same name, same network).

  • i still don't understand what is the issue.

    Auto-connect start with a scan process. During the scan process the device scans each of the enabled channels (see SL_WLAN_GENERAL_PARAM_OPT_SCAN_PARAMS) one-by-one using active scan (sending probe requests and waiting for responses). Once the network list is available, one will be selected for the connection.

    If you have profile with SSID and Password that fits several AP, it should connect to the one with the better RSSI.

    You can read scan result and set higher priority to one of the AP based on its BSSID, but i don't think this was your issue.

    If you think there is a problem with the selection procedure, please provide the NWP log (see chapter 20 in  https://www.ti.com/lit/swru455).

  • Hi Kobi, 

    Thank you for your response, can you tell me if there is a size limit to the "network list"? (

    In the area where the modules operate, there are 29 APs,each serving 4 SSIDs. We want to make sure that the modules are able to find and connect to the best AP.    

    Maxime

  • Hi Maxime,

    Kobi is still looking into this issue, we will update with any new information or solutions. 

    Please note that this week is a short week on account of Thanksgiving, expect a response early next week most likely. 

  • The is 30 entries.

    You can filter the results to include only those with RSSI above a certain threshold or only scan specific channels:

    _i16 Status;
    SlWlanScanParamCommand_t ScanParamConfig;
    ScanParamConfig.RssiThershold = -70;
    ScanParamConfig.ChannelsMask = 0x421; /* channels 1,6,11 */
    Status = sl_WlanSet(SL_WLAN_CFG_GENERAL_PARAM_ID, SL_WLAN_GENERAL_PARAM_OPT_SCAN_PARAMS,
    sizeof(ScanParamConfig), (_u8* )& ScanParamConfig);
    if( Status )
    {
     /* error