Introduction

My idea was to use multiple 802.11b/g units to build a cheap WiFi stumbler using Kismet without the need of hopping channels. If you do not hop you can scan more bands and capture more useful output useful for projects like ​wireless heatmapping.

I went for the RTL8188CUS (Realtek Wireless Chipset, 802.11b/g) because of the cheap pricing.

The Realtek RTL8188CUS comes in many shapes and forms as show on the right. They include labels like:

• WiFi 11N
• EDUP
• IEEE 802.11N
• WiFi N

Comparison

Pro

• The Linux driver is found at ​Realtek Website
• Unit is cheap: ​DX sells them for less than 5 EUR.

Cons

• The driver does not handle multiple cards at the same time.
• No driver support for BSD derivatives.
• Kismet does not seems to support this devices.
• The 802.11N description is properly not valid, nor the driver neither the specifications report this functionality.
• Parts of the drivers are closed source.
• No DataSheet available.

Conclusion

• The units are (currently) not usable for the Wireless Heatmap Multiple Cards project.

Appendix

lsusb -vvv

rvdzwet@bunty:~$ sudo lsusb -s 1:15 -vvv

Bus 001 Device 015: ID 0bda:8176 Realtek Semiconductor Corp. 
Device Descriptor:
  bLength                18
  bDescriptorType         1
  bcdUSB               2.00
  bDeviceClass            0 (Defined at Interface level)
  bDeviceSubClass         0 
  bDeviceProtocol         0 
  bMaxPacketSize0        64
  idVendor           0x0bda Realtek Semiconductor Corp.
  idProduct          0x8176 
  bcdDevice            2.00
  iManufacturer           1 Realtek
  iProduct                2 802.11n WLAN Adapter
  iSerial                 3 00e04c000001
  bNumConfigurations      1
  Configuration Descriptor:
    bLength                 9
    bDescriptorType         2
    wTotalLength           46
    bNumInterfaces          1
    bConfigurationValue     1
    iConfiguration          0 
    bmAttributes         0x80
      (Bus Powered)
    MaxPower              500mA
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        0
      bAlternateSetting       0
      bNumEndpoints           4
      bInterfaceClass       255 Vendor Specific Class
      bInterfaceSubClass    255 Vendor Specific Subclass
      bInterfaceProtocol    255 Vendor Specific Protocol
      iInterface              0 
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x81  EP 1 IN
        bmAttributes            2
          Transfer Type            Bulk
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0200  1x 512 bytes
        bInterval               0
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x02  EP 2 OUT
        bmAttributes            2
          Transfer Type            Bulk
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0200  1x 512 bytes
        bInterval               0
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x03  EP 3 OUT
        bmAttributes            2
          Transfer Type            Bulk
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0200  1x 512 bytes
        bInterval               0
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x84  EP 4 IN
        bmAttributes            3
          Transfer Type            Interrupt
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0040  1x 64 bytes
        bInterval               1
Device Qualifier (for other device speed):
  bLength                10
  bDescriptorType         6
  bcdUSB               2.00
  bDeviceClass            0 (Defined at Interface level)
  bDeviceSubClass         0 
  bDeviceProtocol         0 
  bMaxPacketSize0        64
  bNumConfigurations      1
Device Status:     0x0000
  (Bus Powered)