FCC Permits Frequency Hopping Spread Spectrum Devices in the 2.4 GHz Band

(September 4, 2000) The FCC amended its rules to allow frequency hopping spread spectrum systems in the 2.4 GHz band. The purpose of this rule change is to allow wider bandwidths so that Internet devices will operate at higher data speeds, thereby enabling the development of new and improved products such as wireless computer local area networks and wireless cable modems.

The Federal Communications Commission released its First Report and Order amending Part 15 of the FCC's regulations, which pertains to spread spectrum devices, on August 31.

While the FCC's proceeding was lengthy, complex, and marked by intense debate, the resulting rule changes are short and simple. There are two changes.

First, a new subparagraph (a)(1)(iii) is added to Section 15.247. (This section which covers operation with several bands, including 2400-2483.5 MHz.) The new language is as follows:

"Frequency hopping systems in the 2400 - 2483.5 MHz band may utilize hopping channels whose 20 dB bandwidth is greater than 1 MHz provided the systems use at least 15 non-overlapping channels.  The total span of hopping channels shall be at least 75 MHz. The average time of occupancy on any frequency shall not be greater than 0.4 seconds within a 30 second period."

Second, Section 15.247's subparagraph (b)(1) is revised to read as follows:

"For frequency hopping systems in the 2400-2483.5 MHz band employing at least 75 hopping channels, all frequency hopping systems in the 5725-5850 MHz band, and all direct sequence systems: 1 watt.  For all other frequency hopping systems in the 2400-2483.5 MHz band: 0.125 watts."

At issue is boosting speeds for wireless networks in homes and small businesses. Wire networks are often too expensive or too complicated for ordinary people and small businesses. Wires also prevent roaming about the house with an Internet connected device. And they get in the way.

Many technology companies hope to sell Internet devices, computer peripherals, hardware components, software, or services in this new market. 123 comments, and 13 reply comments, were filed with the FCC in this proceeding, mostly by interested companies.

The FCC opened the proceeding in response to a letter in September of 1998 from the Home RF Working Group, which was organized to represent some of these companies in matters such as this.

However, the FCC also heard from the Wireless Ethernet Compatibility Alliance (WECA), and many of its members, who argued that the rule change would lead to interference with other devices operating in the 2400–2483 MHz band, and would not accomplish the promised transmission rate increases.

William Kennard

The FCC rejected the arguments of opponents of the rule change.

FCC Chairman William Kennard stated that the new rules "will facilitate development of new high-speed data devices for business and consumer applications such as transmission of CD-quality audio and video streams from home PCs to portable devices. The wider bandwidths will permit these systems to provide higher data speeds, thereby enabling the development of new and improved consumer products such as wireless computer local area networks and wireless cable modems."

Commissioners Harold Furchtgott-Roth and Susan Ness wrote a separate opinion to express their concern "about the effect these changes will have on spread spectrum devices already in the hands of consumers", and in particular, "the potential for interference to existing devices."