Apparatus and methods to provide communications to aerial platforms

Abstract

Apparatus, systems and methods for the provision of high data rate and high throughput communications link for drones, in a bandwidth efficient manner. One set of embodiments describe apparatus and methods to mitigate interference from other systems when using the unlicensed radio frequency bands such as the Industrial Scientific and Medical (ISM) bands. Apparatus and methods are also described to enable association of the drone radio sub-system with an “optimal” cell site, such as when the drone uses a directional antenna beam to maximize system throughput. Configurations of a mechanically steerable directional antenna aperture are also disclosed. Other embodiments describe systems and methods to mitigate excessive amounts of interference, and to provide a reliable communications link for signaling and other mission-critical messages.

What is claimed is: 
     
         1 . Apparatus for receiving broadband access via a network of cell sites comprising one or more base stations, each base station comprising a cell radio sub-system, and a cell antenna sub-system configured to form at least one directional beam; the apparatus comprising:
 a drone radio sub-system, a position location determination unit, and a drone antenna sub-system comprising an antenna aperture configured to form a steerable directional beam;   wherein the drone radio sub-system is further configured to:
 store a plurality of position locations associated with a plurality of cell sites of the network of cell sites; 
 instruct the drone antenna sub-system to steer a beam toward a specific cell site based on a drone position coordinate and a specific position coordinate of the specific cell site; 
 measure a downlink signal quality measurement on a received signal from the specific cell site; and 
 receive uplink signal quality measurements provided within the received signal from the specific cell site, wherein the uplink signal quality measurements are associated with the specific cell site. 
   
     
     
         2 . The apparatus of  claim 1 , wherein the drone antenna sub-system is further configured to steer the antenna aperture on at least one axis to point the steerable directional beam toward the specific cell site. 
     
     
         3 . The apparatus of  claim 2 , wherein the drone antenna sub-system comprises a mechanical steering mechanism configured to rotate the antenna aperture from a center of the antenna aperture. 
     
     
         4 . The apparatus of  claim 1 , wherein the drone radio sub-system is further configured to:
 divide a network coverage area into a number of contiguous geographic bins;   maintain a candidate cell site association table with an entry for each one of the number of contiguous geographic bins;   wherein the candidate cell site association table comprises a list of cell sites that are available to establish a communications link based on an uplink or downlink signal quality; and   for at least one candidate cell site within the list of cell sites:
 measure the downlink signal quality for the at least one candidate cell site; or 
 receive the uplink signal quality from the at least one candidate cell site; and 
 associate with the at least one candidate cell site based at least in part on the uplink or downlink signal quality. 
   
     
     
         5 . The apparatus of  claim 4 , wherein the drone radio sub-system further configured to hand off to a different cell site when the uplink or downlink signal quality of the communications link to the at least one candidate cell site falls below an acceptable threshold. 
     
     
         6 . The apparatus of  claim 4 , wherein the drone radio sub-system is further configured to hand off to a different cell site based on a current position location and the candidate cell site association table. 
     
     
         7 . The apparatus of  claim 1 , wherein the antenna aperture comprises an array of patch elements with at least one row and at least one column of patch elements. 
     
     
         8 . The apparatus of  claim 1 , wherein the drone radio sub-system is configured to create one or more spread channels that spread encoded bits in time or frequency. 
     
     
         9 . The apparatus of  claim 8 , wherein the drone radio sub-system communicates using an Institute of Electrical and Electronics Engineers (IEEE) 802.11-compliant protocol. 
     
     
         10 . The apparatus of  claim 9 , wherein the IEEE 802.11-compliant protocol is further compliant with an IEEE 802.11ac standard. 
     
     
         11 . The apparatus of  claim 8 , wherein the received signal is received over the one or more spread channels. 
     
     
         12 . The apparatus of  claim 1 , wherein the drone radio sub-system communicates using a frequency band associated with an unlicensed shared Industrial Scientific and Medical (ISM) band. 
     
     
         13 . A method for receiving broadband access at a drone, comprising:
 storing a plurality of position location data associated with a network of cell sites;   steering a beam toward a specific cell site of the network of cell sites based at least on a drone position coordinate, and a specific position coordinate of the specific cell site as reflected in the data, the steered beam characterized by at least a frequency within an unlicensed frequency band;   measuring a downlink signal quality measurement on a received signal from the specific cell site; and   receiving an uplink signal quality measurements from the specific cell site.   
     
     
         14 . The method of  claim 13 , wherein the steering comprises mechanically rotating an antenna aperture about a fixed axis. 
     
     
         15 . The method of  claim 13 , wherein the steering comprises electrically forming the beam from a patch array of antenna elements. 
     
     
         16 . A method for providing broadband access to at least one drone, comprising:
 forming at least one directional beam toward the at least one drone within an unlicensed frequency band;   receiving a beam from the at least one drone;   measuring the uplink signal quality from the at least one drone; and   transmitting the uplink signal quality measurements to the at least one drone;   wherein the transmitted uplink signal quality measurements are configured to be used by the drone in configuring at least a portion of the broadband access.   
     
     
         17 . A drone radio sub-system, comprising:
 a position location determination sub-system configured to determine a drone position coordinate; and   a drone antenna sub-system configured to steer a directional radio frequency beam;   wherein the drone radio sub-system is configured to:
 store data relating to a plurality of position locations associated with a network of cell sites; 
 steer the directional radio frequency beam toward a specific cell site based at least on an evaluation of (i) the drone position coordinate, and (ii) a specific position coordinate of the specific cell site; 
 measure a downlink signal quality measurement on one or more received signals from the specific cell site; and 
 receive one or more uplink signal quality measurements from the specific cell site. 
   
     
     
         18 . The drone radio sub-system of  claim 17 , wherein the drone antenna sub-system is configured to generate the directional radio frequency beam within an unlicensed frequency band. 
     
     
         19 . The drone radio sub-system of  claim 18 , wherein the one or more received signals from the specific cell site is/are received within the unlicensed frequency band. 
     
     
         20 . The drone radio sub-system of  claim 19 , wherein one or more received signals from the specific cell site is/are multiplexed in at least one of time and frequency within the unlicensed frequency band.