C ABLE B UILDING DSL B ROADBAND W IRELESS B Volume 1 May 7, 2001 and Wi-Fi—Working Together

etween the home, office together, cover the majority of is now being widely deployed in panies, it also offers the promise of and car, consumers have a wireless communications needs in hotels, airports, coffee shops and universal interoperability. Bplethora of devices where the PAN and LAN arenas. restaurants—anyplace where Bluetooth operates with data content is consumed, transmitted Wi-Fi technology is the wire- mobile professionals need instant rates up to 1 Mbps. The technology and stored, and communications less equivalent of , pro- access to information. also supports up to three 64 Kbps enabled. By putting together a viding seamless connection any- Bluetooth is a short-range, full duplex voice channels or up to portfolio of key technologies in the time, anywhere. In the home, it is ‘ to air’ wireless interface, 7 slaves in the basic piconet, with wireless PAN (Personal Area Net- used to connect multiple PCs, offering adhoc connectivity the ability to connect up to 128 in work), wireless LAN (Local Area peripherals, and the like through between a handful of nodes – the an extended ‘scatternet.’ With 79 Network) and broadband cellular gateways or access points. ‘piconet.’ This allows users to frequencies and 1,600 hops per sec- areas, TI is at the forefront of In the corporate environment, create temporary personal net- ond, the Bluetooth specification delivering totally seamless wireless Wi-Fi technology provides high- works among devices for voice targets an approximate range of 10- connectivity, which offers the user speed connections to the LAN. It and data applications. 20m. With a high output power the ability to run compelling appli- also provides seamless access to The 2.4 GHz wireless link solution (20dBm), longer ranges up cations based on the transmission the same content between the replaces many of the cables used to 100m are possible. of voice, and data content home and office, creating a sim- for device connection today and between any device desired. ple transition between each envi- offers a universal connector for a Solving the integration ronment. Today, users can send diverse range of products. issues Wireless networking and receive data at speeds rang- Through its low cost, very low The seamless utilization of these building blocks ing from 1, 2, 5.5, and up to 11 power and ease of use, Bluetooth technologies is not without its Two basic technologies form Mbps, with performance exten- is well suited for mobile and cellu- challenges. Since both technolo- the foundation for home and sions to higher rates under con- lar products, enabling applications gies operate in the same RF band, office networking: 802.11b (mar- sideration (IEEE 802.11g). It that range across a variety of mar- interference is potentially a con- keted commercially as “Wi-Fi” operates at distances up to 100 kets, such as PC, accessory, print- cern. Coexistence is a high priori- technology) and Bluetooth. Both meters, using direct sequence ing, automotive, consumer and ty to successfully deploy both operate in the 2.4 GHz unlicensed spread spectrum technology. industrial. As a worldwide specifi- technologies in the marketplace. ISM band, and when utilized Additionally, Wi-Fi technology cation adopted by over 2000 com- continued on back page

Bluetooth is a frequency hopping and PBCC technologies, there are Q&A with system that is tolerant of other improvements that can be made. interferers due to its hopping The enhancements that TI has Matthew B. Shoemake nature. IEEE 802.11b devices are been working on make both Q. What are the issues affecting A. Moving devices from the equally tolerant of interferers in devices robust against almost any successful device operation in the 2.45 GHz band to the 5 GHz the band due to the packetized interferer in the band. BB unlicensed 2.45 GHz ISM band? band simply trades one set of nature of transmission and the use interferers for another. The 5 of advanced error control mecha- A. Coexistence issues for any GHz band also has multiple types nisms such as PBCC . unlicensed band are similar, of devices operating in it includ- whether it is the 2.45 GHz, 5 ing high power military and Q. What can be done in the GHz or 900 MHz band. Devices meteorological radar systems. future to enhance coexistence? may operate in the band as long as they meet the regulatory restric- Q. If switching bands is not the A. TI has been working for some tions for that band, which include answer for coexistence, what is? time on improvements to both power and bandwidth limitations Bluetooth and IEEE 802.11b plus other requirements. A. It is important to be tolerant devices to enhance their coexis- of any device that may legally be tence performance. Although TI Q. To improve coexistence, is it certified for operation in the band. Bluetooth and IEEE 802.11b Matthew B. Shoemake, Ph.D. Wireless Networking Manager necessary to move to the unli- Both Bluetooth and Wi-Fi devices devices operate well in each other’s DSP Solutions R&D Center censed 5 GHz band? have been designed to do just this. presence with the use of FHSS Texas Instruments

www.ti.com/sc/bbandweek 972-644-5580 C ABLE B UILDING DSL B ROADBAND W IRELESS

company is offering royalty-free licenses under TI patents required for implementations of IEEE 802.11g based on TI’s submitted proposal, pending ratification. This will allow WLAN manufac- turers to quickly deliver higher performance, interoperable wire- less home and office networking applications such as HDTV and streaming video. The new 802.11g technology that TI has proposed extends the data rate to 22 Mbps. TI has provided samples of this high rate, fully 802.11b back- wards compliant device (ACX 101) to its early access customers. TI has also introduced a new, flexible Bluetooth processor, offering significant reductions in system cost and board space. The point-to-multi- point solution includes the BSN6040 baseband and certified TRF6001 transceiver (RF sensitiv- As a leader in wireless communi- the use of system administrators, type of error control used and the ity –86dBm). Its support for full cations and with strong product supervisory functions, or schedul- length of each packet transmitted rate Bluetooth throughput at 723 developments in both of these key ing services. TI’s experimentation in order to maximize throughput. kilobits per second for DH5 pack- technologies, TI is uniquely posi- with the use of dynamic channel Flow controls also can be used to ets significantly reduces wireless tioned to address these concerns. selection, especially in home envi- regulate transmission rates, allow- data transfer time. TI also has a The company utilized this expert- ronments, indicates positive reduc- ing traffic to be put on hold if bad ROM based chipset (BSN6030). ise to conduct extensive testing and tion of interference and increased channels block transmissions. This integrates a complete Blue- has used the results to contribute to performance for both Bluetooth In summary, both Bluetooth and tooth software stack up to the host the IEEE 802.15.2 Task Force, a and Wi-Fi as close interferers. Wi-Fi technologies have an inher- controller interface (HCI), with no group organized to address the Dynamic channel selection can ent robustness against interference external flash memory required. specific Bluetooth/IEEE 802.11b be achieved by monitoring pack- by virtue of their design specifica- co-existence issues. et error rate, channel noise, chan- tions. Additional mechanisms are In an increasingly mobile society, While the issues exist, the inher- nel multipath, inter-symbol inter- actively being studied to insure consumers are demanding instant ent robustness of each technology ference and received signal greater co-existence of Bluetooth access to communications technol- helps to overcome some of the strength. Power control also and Wi-Fi technology in the same ogy - anytime, anywhere. Wireless interference issues, especially as affects potential interference. device. Transmissions across both networking, through Wi-Fi and the distance between them increas- Coordinating the power supplies networks can be coordinated such Bluetooth, meets this demand. And es. When Bluetooth and Wi-Fi are for both technologies and reduc- that transmissions don’t occur at TI is a key enabler for both of these in the same device or sitting right ing transmit power to minimum the same time, or when one device technologies – working to the ben- next to each other, performance requirements increases the anticipates it will be receiving data. efit of consumers and service degradation is the most notable. capacity per area, while reducing providers today, and in the future. One promising path for harmo- the chance for interference. New trends and products nious co-existence is for both tech- Other mechanisms can be put speed development nologies to avoid using the same in place to achieve coexistence. TI has launched several initia- frequency at the same time. Chan- For data connections, Bluetooth tives to speed the development of nel selection can be performed by devices can adaptively select the improved wireless networks. The

ADVERTISEMENT www.ti.com/sc/bbandweek 972-644-5580