M7350/wlan/tools/dsrc/doxy/faq.dox

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/** @page faq Frequently Asked Questions

<b> Q: </b> How do we use the sample dsrc_config app for multichannel operation?

<b> A: </b> Here is a sample command with options.

@verbatim
  ./dsrc_config -c set_config -o num_channels=2,channel_freq0=5860,channel_bandwidth0=10,
          tx_power0=17,duration0=500,guard0=100,channel_freq1=5900,channel_bandwidth1=10,
          tx_power1=17,duration1=500,guard1=100
@endverbatim

@note Do not use spaces in the list of options after -o

This command starts alternate channel switching between the channels specified in channel_freq0 and channel_freq1 (5860 MHz and 5900 MHz, respectively, in this example).
The dwell time in msec on each channel is specified in duration0 and duration1 (500 msec in this example).
The guard0 and guard1 times in msec specify the time to wait before transmitting data after a channel change (100 msec in this example).

<b> Q: </b> How do we test three devices using sample apps?

<b> A: </b> DUT #1  Tx  dual channel with 1pps. The dsrc_tx app will run twice (once in the background) to transmit on each of the two channels.

@verbatim
  ./dsrc_set_chan -c num_channels=2,channel_freq0=5870,channel_bandwidth0=10,
                                    channel_freq1=5900,channel_bandwidth1=10
  ./dsrc_tx -c 5870 -p 1 -m 0 -a 1 -x 5000& ./dsrc_tx -c 5900 -p 1 -m 0 -a 1 -x 5000
@endverbatim

DUT #2 Rx single channel without 1pps
@verbatim
  ./dsrc_set_chan -c 5870
  ./dsrc_rx
@endverbatim

DUT #3 Rx single channel without 1pps
@verbatim
  ./dsrc_set_chan -c 5900
  ./dsrc_rx
@endverbatim

<b> Q: </b> Is freq0 the Control Channel and freq1 the Service Channel in the app command line options?

<b> A: </b> Yes. The channel specified in channel_freq0 will be scheduled for the time slot aligned with the 1pps interrupt.
This behavior corresponds to that of the Control Channel, as explained in the IEEE 1609.4.

<b> Q: </b> What are the default duration and guard times the in dsrc_set_chan sample app?

<b> A: </b> Duration = 50 msec, Guard = 4 msec
@newpage
<b> Q: </b> Are guard0 and guard1 part of duration0 and duration1?<br>
For example, if duration0/1=500, guard0/1=100:
- Tx/Rx on freq0: 400 msec
- Guard time before switching to freq1: 100 msec
- Tx/Rx on freq1: 400 msec
- Guard time before switching to freq0: 100 msec

<b> A: </b> Yes. If you set duration0/1=500 and guard0/1=100, the time on each channel will be 400 ms plus 100 ms guard.

<b> Q: </b> How do I do continuous Tx using the dsrc_tx sample app?

<b> A: </b> Use the "-x 0" option.

<b> Q: </b> Is sending Timing Advertisements supported?

<b> A: </b> Yes, Timing Advertisement broadcasts are supported.
This requires the application to send the UTC time to the modem using the following API:
@verbatim
  int dsrc_ocb_set_utc_time(char *interface,
                        uint8_t time_value[DSRC_OCB_UTC_TIME_LEN],
                        uint8_t time_error[DSRC_OCB_UTC_TIME_ERROR_LEN]);
@endverbatim

A PPS signal is needed to synchronize the time.

Here is the procedure:<br>
You need two devices, one for Tx and one for Rx.

Tx DUT<br>
Connect 1pps

@verbatim
  ./dsrc_set_chan -c 5870
  ./dsrc_config -c set_utc
  ./dsrc_config -c start_ta -r 3 -o channel_freq0=5870
@endverbatim

The -r value is how many TAs will be sent in a 5 sec period (3 in 5 sec in this case).<br>
Let the TA run for a while.<br>
Stop the TA.

@verbatim
  ./dsrc_config -c stop_ta
@endverbatim

Rx DUT

@verbatim
  ./dsrc_set_chan -c 5870
@endverbatim

<b> Q: </b> Does Timing Advertisement work in dual channel mode (both CCH and SCH)?

<b> A: </b> No. TA only works for a single channel.
If channels 5900 and 5860 are configured for switching:

@verbatim
  ./dsrc_config -c start_ta -o channel_freq0=5900 -r 3
         //After this request, TA will be sent on 5900
  ./dsrc_config -c start_ta -o channel_freq0=5860 -r 3
         //After this request, TA will be stopped on 5900 and sent on 5860.
@endverbatim

<b> Q: </b> Does "dsrc_config -c set_utc" get the UTC time from the kernel, and is a value needed for the command?

<b> A: </b> Yes, it sends system time in UTC format to the host driver. No value is needed.

<b> Q: </b> How do I view the Tx output on a spectrum analyzer?

<b> A: </b> Run the Tx sample app in continuous mode with a high payload:

@verbatim
  ./dsrc_tx -c 5870 -p 1 -m 0 -a 1 -x 0 -l 1400
@endverbatim

<b> Q: </b> Are Immediate SCH access and Extended SCH access supported?

<b> A: </b> Yes. If a single channel is configured, it switches to the specified channel immediately.<br>
Or, if already using that channel, it keeps using that channel.

<b> Q: </b> What happens in the following scenario?
   - Device A is running in 2 channel mode; 5860=CCH, 5900=SCH
   - Device B is running in 1 channel mode but switches to 2 channel mode

In this case, what might happen?
   - When device A uses CCH, device B uses SCH
   - When device A uses SSH, device B uses CCH

<b> A: </b> When device B switches to dual channel mode, it will pause scheduling until the nearest time for CCH to be
scheduled so that it will be synchronized to the next PPS. The prerequisite is that both devices have a reliable PPS.

<b> Q: </b> What is the max WSMP packet size that QCA6584.LE.1.0.3 supports?

<b> A: </b> The max size of the Ethernet packet in the host driver is 1500 bytes. The max size of a WSMP packet is 1458 bytes, which is 1500 bytes minus the Ethernet header and the TX control header.
Even though 802.11 allows packets larger than 2000 bytes, the host driver and firmware do not support that because they were written to be compatible with 802.3, which has a max size of 1500.
*/