4.9 GHZ BAND FOR SUPPORT OF PUBLIC SAFETY SERVICES
In 2003, the U.S. Federal Communications Commission (FCC) allocated 50 MHz of spectrum in the 4.9 GHz band to public safety services
1. Public safety agencies can use this 4.9 GHz band to implement wireless networks with advanced services for the transmission of mission-critical information such as streaming video, data access, maps, and missing person images. The FCC intended to accommodate a variety of new broadband applications such as high-speed digital technologies and wireless LANs for incident scene management, dispatch operations, and vehicular operations.
4.9 GHz SUPPORT FROM CISCO
® supports 4.9 GHz technology through its 3200 Series of wireless and mobile routers. Providing a best-in-class solution, the Cisco 3200 Series is an ideal platform for U.S. public safety agencies to use in taking advantage of this new licensed spectrum. Cisco 3200 Series routers can be deployed as rugged outdoor wireless routers with integrated support for 4.9 GHz wireless interface cards (WICs), creating high-speed wireless coverage areas. These high-speed wireless networks are referred to as Cisco Metro Mobile Networks (MMN), combining state-of-the-art Layer 2 wireless and Layer 3 mesh topology IP networking to deliver citywide and statewide broadband wireless access. The Cisco 3200 Series can also be deployed in public safety vehicles to create a mobile network, giving users "always-on" connectivity even while roaming between multiple wireless WAN technologies.
4.9 GHz can be used to connect the vehicle network with high-speed data connectivity, avoiding some of the challenges of unlicensed technologies when deployed in an outdoor environment. The Cisco 3200 Series can provide network connectivity to multiple devices in the vehicle such as laptops, video cameras, printers, and digital video recorders. It can also create a vehicle hotspot with an integrated 4.9-GHz or 802.11 access point. This allows the user wireless access in and around the vehicle with a laptop or handheld device, with the ability to connect to the main network through the router even if that device does not have a 4.9-GHz radio. As part of a Metro Mobile Network solution, the Cisco 3200 Series, now with 4.9-GHz support, provides a scalable, secure, broadband wireless networking solution for public safety agencies.
All state and local government entities that provide public safety services (defined as being focused on the protection of the safety of life, health, or property) are eligible to apply for a 4.9-GHz license. Entities that do not meet these eligibility requirements, but that provide services in support of public safety (for example, private infrastructure companies), can negotiate sharing agreements with license holders.
A 4.9 GHz band license gives the licensee authority to operate on any authorized channel in this band within the applicant's legal jurisdiction (city, county, state, etc.)
2. The 4.9 MHz band is shared by all licensees, who must coordinate usage of the band with other licensees within their areas of authority. Licenses are granted for a term of 10 years. See section below for additional details on the license process with the FCC.
The license gives authority to construct and operate:
• Any number of base stations anywhere within the area authorized by the license3
• Base and mobile units, including portable and handheld units
4.9 GHZ BAND PLAN
The 4.9 GHz band ranges from 4940.5-4989.5 MHz and can be broken out using 1, 5, 10, 15, and 20 MHz of bandwidth. Table 1 illustrates 1-MHz channel bandwidth.
Table 1. 4.9 GHz Band Plan for 1 MHz Channel Bandwidth
Center Frequency (MHz)
Channel Bandwidth (MHz)
2 A 4940-4990-MHz band license will be issued for the geographic area encompassing the legal jurisdiction of the licensee or, in case of a nongovernmental organization, the legal jurisdiction of the state or local governmental entity supporting the nongovernmental organization.
3 There are several exceptions to the licensing of base stations. A station is required to be individually licensed if one of the following conditions is met:
(i) International agreements require coordination
(ii) Submission of an environmental assessment is required
(iii) The station would affect the radio quiet zones
The FCC adopted two emission masks for use in the 4.9 GHz band: the DSRC-A mask for "low-power" applications only, and the DSRC-C mask for "high-power" applications
4. The DSRC-A mask is identical to the mask defined in the widely used 802.11Wi-Fi standard, which is mostly used for in-home wireless LANs and consumer "hotspots" in businesses, ranging from coffee shops to airports. In general, these applications use low-power devices that require less stringent fidelity and limited range. These devices are readily available on the market and reduce cost and time to market for wireless deployments. Higher power units (of above 20 dBm of power output) are required for deploying MMN networks and need to employ the DSRC-C mask.
The transmitting power of stations operating in the 4940-4990 MHz band must not exceed the maximum limits in Table 2.
Table 2. Peak Transmit Power Limits5
Channel Bandwidth (MHz)
Class A Peak Transmitter Power (dBm)
Class B Peak Transmitter Power (dBm)
COMPARISON OF 802.11 AND 4.9 GHZ TECHNOLOGIES BASED ON CISCO IMPLEMENTATION
Table 3 gives a brief overview of the 802.11 and 4.9 GHz technologies.
Table 3. Overview Comparison of 802.11 and 4.9 GHz Technologies
• 5 GHz/U-NII
• 2.4 GHz/ISM
• 4.9 GHz/FCC-licensed
• Lower/middle U-NII: 200 MHz
• Upper U-NII: 100 MHz
• 84 MHz (for both FCC and ETSI)
• FCC: 50 MHz
• 20 MHz
• 22 MHz
• 5, 10, and 20 MHz
• Lower/middle U-NII: 8 channels
• Upper U-NII: 4 channels
• 3 channels (for both FCC and ETSI)
• 10 5 MHz channels
• 4 10 MHz channels
• 2 20 MHz channels
Effective Isotropic Radiated Power (EIRP)
• Lower U-NII: 22 dBm
• Middle U-NII: 29 dBm
• Upper U-NII: 35 dBm
• FCC: 36 dBm
• ETSI: 30 dBm
• 5 MHz channel: 36 dBm
• 10 MHz channel: 39 dBm
• 20 MHz channel: 42 dBm
Cisco Compliance with FCC 4.9 GHZ Regulations
The Cisco 4.9 GHz Wireless Mobile Interface Card (WMIC) is fully compliant with the FCC regulations. The Cisco 4.9 GHz WMIC employs a high fidelity "high power" mask for all transmitted data. This results in higher signal quality and reduced inter-channel interference, which facilitates flexibility in channel reuse and increased Metro Mobile Network scalability.
An application for a license to operate at 4.9 GHz is filed using the FCC's Universal Licensing System (Figure 1). To file for a license, log onto the FCC's Universal Licensing System at
Figure 1. FCC Universal Licensing System
When you click on `Online Filing,' you will be prompted to enter your FCC registration number (FRN). If you are not registered with the FCC, you can register using your Taxpayer Identification Number (TIN). The Webpages will guide you through the remainder of the process for filing for a 4.9 GHz license.
PUBLIC SAFETY BROADBAND WIRELESS COMMUNICATIONS SCENARIOS
The Cisco 4.9 GHz Wireless Mobile Interface Card (WMIC) for Cisco 3200 Series routers provides the foundation for 4.9 GHz-based broadband wireless metropolitan networks. As a licensed wireless technology, 4.9 GHz eliminates interference from unauthorized users, and facilitates large-scale wireless deployments for public safety applications.
For more information about the Cisco 4.9 GHz WMIC and Cisco 3200 Series wireless and mobile routers, visit
http://www.cisco.com/go/3200 or contact your local account representative.