# Presentation: 311716

## Using License Exempt Spectrum for Wireless Broadband

**Ronald Repasi, Deputy Chief****  **
**Office of Engineering and Technology **
**Regional Educational Workshop**
**On Rural Broadband**
**June 19, 2008**

** ****Note: The views expressed in this presentation are  those  of the author and may **
**not necessarily represent the views of the Federal Communications Commission**

## Unlicensed Devices: Part 15

**Unlicensed Devices: Part 15**

- Part 15 provides for operation of low power radio transmitters without a license
- Operating conditions:
**May not cause harmful interference**
**Must accept any interference received**
- Part 15 minimizes likelihood of interference by:
**Permit operation in non-restricted frequency bands**
**Limiting power to very low levels**
**Requiring equipment approval to ensure compliance**

## Technical Requirements

**Technical Requirements**

- Almost any spectrum can be used except certain restricted frequency bands (Ref. Section 15.205)
- On most frequencies, operation is limited to < 100 mW;  duty cycle applies in some cases
- Three (ISM) bands allow 1 W transmitter power:
- 902-928 MHz
- 2400- 2483 MHz
- 5725 – 5875 MHz
- Power reduction for antenna gain > 6 dB

## More Spectrum Made Availablefor Unlicensed Operation

**More Spectrum Made Available****for Unlicensed Operation**

**50 mW**
**Indoor Use Only**

**250 mW**

**    **
**    ****1 W**

- 5150

- 5250

- 5350

- 5725

- 5825

- Frequency (MHz)

- Link
- Indoor
- Devices

- Link
- Devices
- to Nodes

- Link
- Nodes
- (Campus)

**  ****FCC has recently made available an additional 255 MHz of spectrum for anticipated Wi-Fi growth**
** ****Provides A Total of 555 MHz of Spectrum for unlicensed operations**

- U-NII Devices

**250 mW**

- 5470

**Existing**

**Existing**

**Existing**

**New**

## Equipment Authorization Required

**Equipment Authorization Required**

- Equipment must be authorized by FCC or telecommunications certification body
- Equipment may not be imported or marketed until certificated
- Check label for FCC ID
- Grants of certification available on FCC web site

*http://www.fcc.gov/oet/ea/*

*See*

*FCC Id:  XXXYYYY*

## Wi-Fi: Wireless Fidelity

**Wi-Fi**: Wireless Fidelity

**IEEE Committee 802.11 developed a family of  standards for unlicensed wireless data networks within the framework of the Part 15 rules**

| Standard | Frequency Band | Modulation | Data Rate |
| --- | --- | --- | --- |
| 802.11(b) | 2.4 GHz | DSS | 11 Mb/s |
| 802.11(g) | 2.4 GHz | OFDM | 54 Mb/s |
| 802.11(a) | 5.8 GHz | OFDM | 54 MB/s |

**Notes:**
IEEE 802.11b, which is now known as Wi-Fi, was developed primarily as a  wireless network standard. 

 It uses direct sequence spread spectrum technology in the 2.4 GHz band.  

Most Wi-Fi devices use less than 100 mW of power, with an operating  range of 100 m indoors and up to 300 meters outdoors.  

Wi-Fi can achieve a data rate of up to 11 Mb/s.

## Wi-Fi: MiMo Technology

**Wi-Fi: MiMo Technology**

- MIMO: Multiple Input Multiple Output
- New generation of consumer products
- Based on IEEE 802.11 standard
- Allows greater range and data throughput

## Wi-Fi Applications

**Wi-Fi Applications**

**Metropolitan & Community **
**Networks – WISPs**

**“****Hot Spots” at coffee shops, hotels, airports, etc.**

**Home & Business **
**networking**

**Notes:**
One of the more popular applications for IEEE 802.11b is for wireless computer networks, particularly by education, health care, and financial institutions, and a wide assortment of businesses.  

One interesting recent development is the configuration of these networks as internet access points at public gathering places such as airports and restaurants.  

These same devices are also being used by some internet service providers to set up community wireless networks, particularly in rural areas.

## Basic Network Architecture

**Basic Network Architecture**

*Fixed Radio Transceiver*

*Internet Connection*

*High Gain *
*Antenna*

*High Gain *
*Antenna*

*20 – 40 Miles*

*Licensed:  Wi-Max or other technology*

*Unlicensed:  Wi-Fi; Canopy or*
*             **other technology*

*Fixed Radio Transceiver*

*100 meters per LAN*
*Or integrated to network*

##  Wi-Fi Mesh Networks

** ****Wi-Fi Mesh Networks**

- Mesh networks use each transmitter/receiver as a relay point to provide wide service areas.  They are self-forming and provide numerous communication paths- - same principle as the Internet

- Laptop
- with Wi-Fi

-  Laptop
-  with Wi-Fi

## Mesh Network Coverage

**Mesh Network Coverage**

**Conventional **
**Network**

**Mesh**
**Network**

**Adequate **
**Signal**

**Inadequate **
**Signal at**
**Remote Locations**

**Adequate **
**Signal**

**Signals are**
**relayed to **
**remote locations**

## Example of a Mesh Network

**Example of a Mesh Network**

- City of Chaska, Minnesota
- 2000 Wi-Fi subscribers over an area of 16 square miles
- Provided by routers mounted on lamposts - - 15 minute install time
- Consumer data speeds  of to 1.2 MB/s
- See www.Chaska.net

## WISP Resources

**WISP Resources**

- Search: Wireless Internet Service Providers
- WISPA.Org – Includes information on how to establish a WISP
- Part-15.org
- Vendor web sites

## Integrating Licensed & Unlicensed

***Integrating Licensed & Unlicensed***

- Business
- Access &
- Backhaul

- Hotspot
- Backhaul

**W-Fi**

**802.11**

- Directly to Indoor Modem

**Portable Devices**

*WiMAX technology can operate in licensed or unlicensed spectrum:*

## 
Thank you!

Ronald.Repasi@fcc.gov

- Thank you!
_**Ronald.Repasi@fcc.gov**_

**Conclusion**

**Notes:**
That concludes my formal presentation and I look forward to your questions later in the day.