I don't know how known about these are but I don't recall mention.

Integrated pop on your board and go WiFi modules with free PIC TCP/IP
stack, own MAC address,
integrated aerial or not versions, "up to 400m range"* , precertified
for US,  Canada, Europe, Japan.
* Much more or much less deepending what you do next.

802.11 BGN 36 PIN SMD MODULE 21 mm x 31 mm, 3V.

  MRF24WB0MARM        Datasheet

     http://ww1.microchip.com/downloads/en/DeviceDoc/70632A.pdf

Microchip budgetary price ~$US30/1-25 not dropping much at 5000 rate.
Mouser shows stock.

=95IEEE Std. 802.11-compliant RF Transceiver
=95Serialized unique MAC address
=95Data Rate: 1 and 2 Mbps
=95IEEE Std. 802.11b/g/n compatible
=95Small size: 21mm x 31mm 36-pin Surface Mount Module
=95Integrated PCB antenna (MRF24WB0MA)
=95External antenna option (MRF24WB0MB) with ultra miniature coaxial
(U.FL) connector
=95Range: up to 400m (1300 ft.)
=95Easy integration into final product =96 accelerates product
development, provides quicker time to market
=95Radio regulation certification for United States (FCC), Canada (IC),
Europe (ETSI) and Japan (ARIB)
=95Wi-Fi=AE certified (WFA ID: WFA7150)
=95Designed for use with Microchip microcontroller families (PIC18,
PIC24, dsPIC33, and PIC32) with downloadable Microchip TCP/IP Stack

RF/Analog Features:
=95ISM Band 2.400-2.483.5 GHz operation
=9514 Channels selectable individually or domain-restricted
=95DSSS Modulation
=95Data Rate =96 1000 kbps
=95-91 dBm Typical sensitivity at 1 Mbps
=95+10 dBm Typical output power with control
=95Integrated low phase noise VCO, RF frequency synthesizer, PLL loop
filter and PA
=95Digital VCO and filter calibration
=95Integrated RSSI ADC and I/Q DACs, RSSI readings available to host
=95Balanced receiver and transmitter characteristics for low power consumpt=
ion

MAC/Baseband Features:
=95Hardware CSMA/CA access control, automatic ACK, and FCS creation and che=
cking
=95Automatic MAC packet retransmit
=95Hardware Security Engine for AES and RC4-based ciphers
=95Supports 802.1x, 802.1i security


_RF _WiFi _PIC _Microchip

E&OE

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