What is TV White Space (TVWS)?
TVWS operates over of unused channels in the analog TV spectrum to project wireless along great distances (5+ miles). The thing that sets TVWS apart from other wireless bridge solutions is that it does not require a direct line of sight, and can penetrate some tree/terrain coverage.
Hows does it work?
A host site places a "base station" and antenna on the roof or a pole on their property. Client stations are set up nearby to receive the signal provided by the base station and convert it back to a connection that can then be shared out via a normal wireless access point at the client site. Usually, a single base station can support many client stations.
What kind of distances can be achieved?
This depends on the hardware! Lower-cost options often max out at about 5 miles of range (expect 2-3 with obstacles and minor interference), where as more expensive solutions can go much greater distances, sometimes as much as 30 miles!
How much does the hardware cost?
This varies depending on the distance you plan to cover, and the manufacturer you work with. We recommend expecting a very basic roll-out with a single client station to cost at least $5,000, and a 360 coverage configuration with a handful of client locations to cost closer to $15,000. One of the great benefits of TVWS is that this shares your existing internet connection at your library, keeping you from worrying about monthly internet costs or client side filtering solutions.
Where can I see TVWS channel availability in my area?
Check out the Nominet tool to see if TVWS will work for you! We recommend setting the height to 10, and looking for a minimum of 9 channels. Contiguous channels allow for bonding, increasing throughput which translates to internet speed for your users! These channels can change from time to time, but we also have a list of all libraries in Georgia and their channel availability pulled mid 2020.
How does this work with E-Rate?
E-Rate allows for wireless within the borders of your library property. When you share your connection "beyond the walls" of you library, e-rate cannot be used to cover that portion of your internet. To resolve this issue, we recommend dedicating a percentage of your internet connection to solutions outside of your library, and requesting e-rate reimbursement for only the percentage that stays within your library. For example: Library A has 100 Mbps of internet speed at their branch. The library sets up TVWS and dedicates 20 Mbps of that connection (20%) to support their new TVWS infrastructure. They then change their E-rate reimbursement request to only ask for 80% of their total internet bill, the portion that stays at their library, and pay out of pocket for the 20% that is dedicated to TVWS. See example here.
Do we have to license channels or manage their availability?
No, this is all managed by the TVWS hardware. TVWS devices report their location and check with a database to determine what channels are available in their area. This check is repeated at specified intervals or if the device is moved to make sure the device is only using available channels in the area.
What vendors are available?
Some of the vendors we are aware of:
Examples of TVWS implementations:
TVWS in the news:
Where can I get more information?
Suggested steps for implementation:
Identify branches/locations of interest and need.
Take a look at the GBDI Unserved map to see where need is greatest.
Verify spectrum availability of locations.
Determine portion of internet that can be dedicated, adjust E-Rate to determine monthly costs.
E-Rate will not cover library extending internet. Therefore you will need to dedicate a % of incoming bandwidth for TVWS and remove that % from your E-Rate reimbursement request, or use a secondary network that is not E-Rate eligible to host TVWS.
Identify client sites/locations.
Request verbal approval for testing and potential install from location managers/owners. Don't worry about getting something in writing yet. This is just for testing.
Verify base station and client locations with on-site spectrum analyzer/TVWS hardware or discuss location with TVWS reseller.
TVWS hardware can do a RF sweep, or you can use a tool like this handheld analyzer.
Provide results to TVWS reseller to confirm and purchase required equipment.
Install and setup TVWS equipment. Install local AP for each client location to provide standard wireless access.
Hardware required beyond TVWS equipment: network cable and power to pole or roof of host site, hardware mounting solution, network cable, power, mounting solution, and wireless access point at client site.
Track the wireless sessions and bandwidth usage to each client site, and use the data to inform additional implementations and location choices.