Wireless Communications

Wifi connection management can be a bit fiddly on Windows Mobile, but WeFi looks like it might be a step in the right direction. When activated, the app searches for nearby wifi hotspots and grade the quality of their connection before connecting you to the best. You can specify an app to launch as soon as a connecton is made and WeFi will also alert you if your IM contacts are online. Here is a quick YouTube clip showing the app in action:

O’Reilly Radar is reporting news of a new web service that claims to offer real time decryption of the GSM protocol. Cracking GSM encryption has always been a computationally intensive process but thanks to a technique known as Rainbow Tables (essentially, this just means working out a lot of the hard sums in advance and storing the answers in a huge lookup table) a lot of the work has already been done. The other ingredient is a device called a Universal Software Radio Peripheral (USRP) - unlike most receivers that can pick up, say, FM transmissions, TV or mobile phone signals the USRP can receive the lot. It is relatively simple to program the device to isolate particular signals and these are then digitised for analysis by the cracking service. What does this mean for the security of GSM phone calls? Well, according to O’Reilly, the service should let you grab a live GSM call and begin listening in on it within 30 seconds. The article (and the researchers behind the service) are at

Chipset BlueCore4-Ext bt ~ # hciconfig hci0 up bt ~ # hciconfig hci0 revision hci0: Type: USB BD Address: xx:xx:xx:xx:xx:xx ACL MTU: 384:8 SCO MTU: 64:8 HCI 19.2 Chip version: BlueCore4-External Max key size: 56 bit SCO mapping: HCI bt ~ # hciconfig hci0 -a hci0: Type: USB BD Address: xx:xx:xx:xx:xx:xx ACL MTU: 384:8 SCO MTU: 64:8 UP RUNNING RX bytes:79 acl:0 sco:0 events:8 errors:0 TX bytes:30 acl:0 sco:0 commands:8 errors:0 Features: 0xff 0xff 0x8f 0xfe 0x9b 0xf9 0x00 0x80 Packet type: DM1 DM3 DM5 DH1 DH3 DH5 HV1 HV2 HV3 Link policy: Link mode: SLAVE ACCEPT Name: 'NET' Class: 0x1c010c Service Classes: Rendering, Capturing, Object Transfer Device Class: Computer, Laptop HCI Ver: 2.0 (0x3) HCI Rev: 0x77b LMP Ver: 2.0 (0x3) LMP Subver: 0x77b Manufacturer: Cambridge Silicon Radio (10) -----------------------------------------

Radio Common Tx/Rx terminal simplifies external matching; eliminates external antenna switch BIST minimises production test time. No external trimming is required in production Full RF reference designs available Bluetooth® v2.0+EDR specification compliant (v2.1 upgradeable) Transmitter +6dBm RF transmit power with level control from on-chip 6-bit DAC over a dynamic range >30dB Class 2 and Class 3 support without the need for an external power amplifier or Tx/Rx switch Supports Π/4 DQPSK (2Mbps) and 8DPSK (3Mbps) modulation Receiver Integrated channel filters Digital demodulator for improved sensitivity and co-channel rejection Real time digitised RSSI available on HCI interface Fast AGC for enhanced dynamic range Supports pi/4 DQPSK and 8DPSK modulation Channel classification Synthesiser Fully integrated synthesiser requires no external VCO, varactor diode, resonator or loop filter Compatible with crystals between 8 and 32MHz (in multiples of 250kHz) or an external clock Accepts 7.