Enabling Procedure of Communication in TVWS under FCC rules

1. Enabling Procedure of Communication in TVWS under FCC rules Authors: Date: 2009-02-28 Notice: This document has been prepared to assist IEEE 802.11. It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein. Chen SUN, NICT

2. Abstract • By drawing an analogy between 802.11y STAs and FCC devices, we can see that DSE in 802.11y can be adopted for 802.11af with some modification. • Additional steps are added to satisfy the FCC regulation. • The devices discussed in this presentation are assumed to be personal/portable devices and fixed station both with no geolocation/access to database. • The document presents solution to enable communication to satisfy mandatory FCC rules. • In addition, a solution is given to enable communication not only to satisfy mandatory FCC rules but also to have additional benefits such as better incumbent user protection, reduced transmit power, etc. Chen SUN, NICT

3. Analogy of devices in 802.11y and FCC regulation • 802.11y • Registered STA • Fixed STA • Enabling STA • Unregistered STA • Dependent STA • FCC • Having geolocation capability and access to database • Fixed device (<4w) • personal/portable devices in Mode-II (<100mw) • No geolocation capability/access to database • Mode-I devices (<100mw) and sensing only devices (<50mw) • Fixed TVBD device does not have a direct connection to the Internet and has not yet been initialized and registered with the TV bands database (fixed-client). Chen SUN, NICT

4. FCC regulations • Before operation • FCC15.13(e) Check with TVWS database (for fixed devices and Mode II master devices) • FCC 16.711(C-3): TV channel availability check time. A TVBD is required to check for TV signals for a minimum time interval of 30 seconds. • During operation • FCC 15.711(c-4): In-service monitoring. A TVBD must perform in-service monitoring of an operating channel a minimum of once every 60 seconds. • FCC 15.711(c-5): Channel move time. After a wireless microphone or other low power auxiliary device signal is detected on a TVBD operating channel, all transmissions by the TVBD must cease within two seconds. Chen SUN, NICT

5. FCC rules regarding to Mode I devices • Mode I - client, whereby a personal/portable device is controlledby a fixed or a personal/portable device operating in Mode II that has determined the available channels in the area. • 133 We envision that both the Mode I and Mode II approaches will often be incorporated into the same personal/portable device. That is, a personal/portable device could function as a master device when it is able to use geolocation/sensing and database access to identify unused TV channels in its area. If it cannot rely on these techniques but is near a fixed device or another personal/portable device that can act as a master, it could operate in client mode if it makes contact with a master station. • 15.711 (b-iv): Personal/portable devices operating in Mode I shall obtain a list of channels on which they may operate from a master device. • 15.711 (g) A personal/portable TVBD operating in Mode I may only transmit upon receiving the transmissions of fixed or Mode II TVBD. A personal/portable device operating in Mode I may transmit on either an operating channel of the fixed or Mode II TVBD or on a channel the fixed or Mode II TVBD indicates is available for use.

6. DSE in 802.11y and necessary modifications • The DSE operating procedures are used to automate the channel permissioning and regulatory controls needed for unregistered IEEE 802.11 STAs to operate as dependent STAs in licensed spectrum. • Spectrum sensing steep shall to be added to follow FCC rules. • Procedure for making contact with enabling STA, obtaining a list of available channels as well as being under control by the enabling STA should be added. • Transmit power control should be added to provide additional benefits for the operation under FCC rules. Chen SUN, NICT

7. Proposed procedure for 802.11af For this approach, the STA shall obtain a list of available channels and shall become being under control of the enabling STA (Mode II device) after receiving the enabling beacon. Chen SUN, NICT

8. Comparison of the state diagrams of enabling procedure in 802.11af and that in 802.11y Figure 1 DSE in 802.11y Figure 2 Proposed enablement procedure in 802.11af The red color indicates modifications on the DSE of 802.11y. Chen SUN, NICT

9. Proposed procedure for 802.11afwith additional power control • Power control is added to state (9) to start communication with a relatively lower power. • Since the STA has performed sensing and is not yet under control of the enabling STA and haven’t contacted the enabling STA, it can operate as a sensing-only device. • In stage (9), the STA (as a sensing-only device) can make contact with the enabling STA and obtain a list of available channels. • If the STA is under control of the enabling STA, the STA can operate as a Mode I device. Chen SUN, NICT

10. Comparison of the state diagrams of enabling procedure in 802.11af and that in 802.11y Figure 1 DSE in 802.11y Figure 2 Proposed enablement procedure in 802.11af The red color indicates modifications on the DSE of 802.11y. Chen SUN, NICT

11. Conclusion • A procedure (two options) for enablement in 802.11af is given. • The proposed procedure requires some modification of the DSE in 802.11y for the operation to follow FCC mandatory rules. • Additional steps (such as spectrum sensing, transmit power control) are included to satisfy the regulations set by FCC. • The proposed procedure is useful to TVBDs with no geolocation/database access capabilities. • The procedure facilitates manufacturers to produce low-cost commercial 802 products (no geolocation/database access). Chen SUN, NICT