1. Washington Laboratories (301) 417-0220 web: www.wll.com7560 Lindbergh Dr. Gaithersburg, MD 20879 Desert William H. Graff President and Director of Engineering, AmericanTCB

2. What is MIMO?

3. MIMO From a regulatory perspective, MIMO is a multi- antenna version of WiFi All tests are identical to those currently required for 15.247 In most cases, two separate “chained” transmitters operate simultaneously RF power listed on the Grant is the sum of both PA.

5. Most common configuration 2 transmit, 3 receive (2 x 3) MIMO Omni directional antennas Resultant signal propagation is omnidirectional Diversity transmit/receive with a lot of Digital Signal Processing

6. Basic MIMO Block Diagram

7. MIMO and RF exposure No significant change to MPE procedures SAR reports must be more careful in identifying what antennas are used and at what RF power

8. EMC Measurement Considerations Radiated emissions measurements - used standard techniques Antenna conducted emissions - use combiner network Power measurements - use power meter and spectrum analyzer as required by regulations Occupied bandwidth same for each chain Operating frequency same for each chain Theory of Operation must state that both chains operate on same channel at all times without beamforming

9. WiMax No specific spectrum addressed in FCC rules. No specific channelization defined in FCC rules (similar to Part 24). “Free-for-all” Part of FCC’s new “Permit But Ask” procedure Potential applicants are advised to speak to FCC very early in the development stage Follow Part 2 very closely

10. WiMax Documentation Considerations Very important to spend a lot of time on manuals, operational description, etc. FCC has seen few WiMax devices within the 2-2.7 GHz band. FCC’s questions reflect their caution Expect the time line to be long. Our experience would place it at minimum one month from time filing first filed with ATCB Check back with us later! Changes are coming!

11. WiMax SAR Considerations Do not use 2450 MHz dipoles and mixtures for the new frequency range. Make sure your probes are calibrated for the center of the band of interest. Purchase your validation dipoles early! Expect a lot more detailed SAR questions

12. RFID Can exist in many parts of the Rules. Very low-power devices are defined in 15.240 within the 433.5 – 434.5 MHz band Many devices are also available in the 15.247 spread spectrum bands Lots of interest in using frequency hoppers within the 902-928 MHz band at 1Watt Passive tags are not Certified.

13. ZigBee Low-power “node” communication system Low data bandwidth Good for inventory control where “widgets talk to widgets” Data repeaters are possible. Not yet caught on in North America

14. 802.11a / DFS Testing Before 2004, UNII devices (802.11a) were only allowed within the 5150-5250, 5250-5350, and 5725-5825 MHz bands. Industry petitioned for additional spectrum within the 5.4GHz bands. FCC eventually Granted and allotted 5470-5725 band, but in order to preserve spectrum for military radars, DFS protection was introduced. DFS = Dynamic Frequency Selection

15. DFS Testing US military radars have different modulation characteristics from European radars. Therefore EU DFS testing techniques are considerably different from North America. Technical paper available from FCC database.

16. DFS Implementation DFS testing is required now on all 802.11a devices which can function as an access point. Full DFS testing must go through FCC for approvals – TCBs not yet permitted. “Client-Only” devices can go through TCB process, but the must not implement ad-hoc or “peer-to-peer” mode within the 5GHz band.

17. DFS and existing products Non-DFS Class II PC approvals completely cease in July 2007. Only non-DFS devices which never use the DFS bands of 5250-5350 and 5470-5725 MHz can seek approval DFS can be added to a non-DFS device using the Class II PC process. This assumes there is no hardware changes and DFS is simply a software upgrade No “field upgrades” allowed.

18. Permit-But-Ask Procedure New! as of November, 2006 FCC has initiated a new procedure for “troublesome” filings and new technology. Prior to any request for Certification, a TCB must request guidance from FCC on specific items to look for before granting Certification. Specifically aimed (so far) at 15.239 personal FM transmitters, WiMax devices and 3.5/4G cellphones. See FCC Memo to TCBs.

19. Contact Information William H. Graff President and Director of Engineering AmericanTCB, Inc. 6731 Whittier Ave. McLean, VA 22101 mailto: whgraff@ATCB.com Corporate Phone: (703)847-4700 Corporate FAX: (703)847-6888 Direct Mobile: +886 920399260 SKYPE: whgraff