CSR has a wide range of tools to support the development of UniFi™-based 802.11 applications, and brief details will appear in this section as resources are publicly released. However, we also suggest you discuss your your target application with your local CSR office to check what support resources are available.
2 types of support: a development system, and example designs
UniFi applications may be developed in two ways: using a development system, or by using or adapting one of CSR's ready-engineered example designs.
The UniSira development system for Wi-Fi is detailed here.
CSR's 'example designs' provide a pre-designed and tested circuit solution for a particular application, including full circuit and bill-of-material information, and a detailed engineering note to help you understand and apply the design.
Currently, we offer an example design for a voice over Wi-Fi phone, and we have produced demonstration hardware which illustrates the coexistence of Bluetooth and Wi-Fi:
The UniVox design has a very small eBOM and is based on just two major ICs: UniFi, and CSR's own Multimedia applications processor.
Activity signalling between Bluetooth and Wi-Fi elements embedded on this demonstration hardware, in conjunction with unique proprietary coexistence measures, illustrates the virtue of employing CSR's BlueCore and UniFi devices to target emerging cellphone opportunities.
VoWi-Fi phone
CSR's UniVox design for voice-over-Wi-Fi phones sets new standards of performance in this exciting market:
- An exceptionally small bill of materials (less than $15)
- Incredibly low power consumption (up to 20 hours talk/400 hours standby from a 1500mAh battery)
The UniVox design is provided with CSR's UniVox Development Solution (DEV-SYS-UNIVOX-1A). There are no royalties or license fees to pay. Just add your user interface (and optimise the MMI provided - or use it as it is), create the surrounding phone plastics, and it's ready for mass production. More information
Bluetooth / Wi-Fi coexistence
Developers co-locating both Bluetooth and Wi-Fi functions inside a very small form factor such as a cellphone have to contend with 'front-end overloading' (an effect caused by the transmission power levels which - when combined with the proximity the embedded system imposes - are enough to saturate or de-sensitize the front end of the nearby RF chain). Co-ordination using time domain multiplexing (TDM) between the two protocols - also known as Activity Signalling - is required to overcome this, and several proprietary schemes have been devised.
CSR's Bluetooth devices such as the EDR-equipped BlueCore4 support all common coexistence measures developed by Wi-Fi silicon vendors. However, as CSR also manufactures the UniFi 802.11 b/g solution for embedded applications, it's been possible to include further optimization measures. CSR has implemented these additional features, because even when current protection techniques are utilised, there are still coexistence issues. Take the example of someone using Bluetooth for voice communication while also surfing the web. The synchronous Bluetooth SCO connection will be disrupted by the packet reception acknowledgements that Wi-Fi is forced to transmit - resulting in bad voice quality for the Bluetooth link.
We have produced hardware which demonstrates that obtaining both devices from CSR provides access to a ready-engineered coexistence solution. Demonstrations include a VoIP call over a Wi-Fi link using a Bluetooth headset; streaming stereo music to Bluetooth headphones while simultaneously browsing the internet or downloading an MP3 file; receiving a phone call over a Bluetooth headset while surfing the internet; and simultaneous transfer of files over Bluetooth and Wi-Fi links. The TDM and proprietary measures built in the UniFi device (with UMA-compliant 17 dBm radio frequency output power) ensure that synchronous Bluetooth HV3 packets do not cause interference.