Patent Publication Number: US-11653215-B2

Title: Heterogeneous mesh network and a multi-RAT node used therein

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation-in-part of, and claims priority under 35 U.S.C. § 120 to, U.S. patent application Ser. No. 16/013,727, titled “Heterogeneous Mesh Network and a Multi-RAT Node Used Therein” and filed on Jun. 20, 2018, which itself is a continuation of, and claims the benefit of an earlier filing date under 35 U.S.C. § 120 based on, U.S. patent application Ser. No. 14/531,996, filed on Nov. 3, 2014, entitled “Heterogenous Mesh Network and a Multi-RAT Node Used Therein,” which is a division of, and claims the benefit under 35 U.S.C. § 120 of, U.S. patent application Ser. No. 13/889,631, entitled “Heterogeneous Mesh Network and a Multi-RAT Node Used Therein” and filed May 8, 2013, which claims the benefit under 35 U.S.C. § 119 of each of U.S. Provisional App. No. 61/705,440, entitled “Multi-Access and Backhaul Wireless Systems and Methods” filed Sep. 25, 2012; U.S. Provisional App. No. 61/784,002, entitled “Method of Dynamically Altering Operational Parameters of a Base Station,” filed Mar. 14, 2013; and U.S. Provisional Pat. App. No. 61/812,119, entitled “Heterogeneous Mesh Network and a Multi-RAT Node Used Therein,” filed Apr. 15, 2013, each of which are hereby incorporated by reference in their entirety. In addition, U.S. Patent Publication No. 20190364616 A1; U.S. patent application Ser. No. 16/733,947; and International Patent Publication No. WO2019209922 are also hereby incorporated by reference in their entirety. 
    
    
     FIELD 
     The present application relates to mesh networks, wireless mesh networks, heterogeneous mesh networks, self-organizing networks, and methods of creating the same. 
     BACKGROUND 
     Mesh networks have existed on the fringe of the IT world since the early 1980&#39;s. See generally Power Source Online,  Mesh Networks,  Kristin Masters March 2010. http://www.powersourceonline.com/magazine/2010/03/mesh-networks. Recent advancements in wireless technology have promoted further exploration of applications for mesh networks; they hold extensive promise for rich applications such as sensor networks. Id. 
     Typically, a wireless mesh network operates in a homogeneous fashion, meaning that the nodes within the network share certain traits enabling communication between them. An example of this could be a wireless mesh network operating on a Wi-Fi protocol. 
     Before there were wireless communications, telephone calls were placed over wired infrastructure. For wired telephony, there were different wire-line protocols, e.g., ATM and TDM, that the telephone exchanges sought to connect. One way to interconnect these disparate networks was to create gateways that could bridge together the different networks. Although these gateways provided a bridge between networks, it is not always possible for a gateway to transparently connect different nodes from different networks without needing to emulate missing features on one network or to suppress unique features from another. This gateway paradigm has been used in wireless technology as well, one example being a personal Wi-Fi portable access point that connects to the Internet using a 3G or 4G cellular data connection. 
     Recently, some have studied the benefits of connecting heterogeneous mesh networks. For example, You, L. et al., noted “One of the key issues is networking, which means to interconnect lots of networks, such as internet, cellular networks, wireless sensor networks (ZigBee), wireless-fidelity networks (Wi-Fi), social networks, etc.”  FHMESH: A Flexible Heterogeneous Mesh Networking Platform,  You, L. et al, IEEE Sixth International Conference on Mobile Ad Hoc and Sensor Networks, Dec. 20, 2010. This paper noted that finding an efficient way to interconnect these networks is an ongoing challenge in the Cyber Physical Systems field. Id. The authors of this paper designed a “platform utilize[ing] WMN technology to interconnect heterogeneous networks, and buil[t] gateways based on SDR technology.” Id. 
     Others who have sought to combine heterogeneous mesh networks have taken a similar tack. For example, heterogeneous interfaces for mesh networks typically consist of gateways that act as bridges between the two separate mesh networks. These gateways often employ Software Defined Radio “SDR” technologies. In effect, these gateways act as translators between the two disparate mesh networks. The individual nodes in the two disparate mesh networks, however, do not communicate directly with one another. They can only communicate via the gateway. 
     There are many benefits to creating heterogeneous mesh networks including increasing capacity without increasing costs. Increased capacity is desirable under many scenarios including in emergency situations such as the Sep. 11, 2001 attack on New York City, hurricanes Katrina and Sandy, and most recently, the Boston Marathon bombings. In the eleven-plus years that have transpired between the 9/11 events and the recent Boston Marathon bombing, there have been enormous advances made in wireless communications. Reliability and capacity have increased tremendously during that timeframe. But in emergency situations, cellular networks are still not able to handle the increased demand for telephone and data services. 
     “Toward the bottom of the list of disturbing aspects about Monday&#39;s bombing at the Boston Marathon was this: Cellular networks in the area almost immediately slowed down and, for periods of time, appeared to stop working altogether. Runners and their loved ones could not connect, and victims had trouble communicating with emergency responders. That frustrating scene has become familiar, evoking disasters from the September 11th attacks in 2001 to Hurricane Sandy in 2012. We rely on cell phones to run our lives, but they tend to be useless—or at least far from useful—when we need them most . . . . The science behind these failures in wireless connectivity isn&#39;t complicated. In every city, each mobile carrier operates hundreds or thousands of cell towers, which route calls and data to the carrier&#39;s backbone network. Each tower is designed to accommodate a set number of calls per second, per a certain geographic area. In a crisis, when everyone naturally reaches for their phone, that limit is quickly surpassed and the radios on the tower get sluggish. Mobile analyst Chetan Sharma, who estimates that a cell site can handle 150 to 200 calls per second per sector: ‘We&#39;ve all had the experience of a fast-busy signal. That is the network telling you, “Sorry, but your cell is overloaded. There is no more space.”’ Brad Stone,  Why Cell Phone Networks Fail in Emergencies,  Bloomberg Businessweek Technology, Apr. 16, 2013. http://www.businessweek.com/articles/2013-04-16/why-cell-phone-networks-fail-in-emergencies 
     In order to increase capacity and utilize all possible resources presently available, it is desirable to create a heterogeneous mesh network where the nodes themselves provide the heterogeneity. If, for example, in the minutes after the bombing at the Boston Marathon, traffic had been rerouted, not to user&#39;s designated backhaul locations, but instead to backhaul locations that were geographically further away, e.g., Cambridge, South Boston, or Chelsea, there would have been more backhaul available on these networks to facilitate data transmission. The present invention addresses this need. 
     SUMMARY OF THE INVENTION 
     This invention discloses a heterogeneous mesh network comprised of multiple radio access technology nodes. In this heterogeneous mesh network, nodes can function dynamically, switching roles between client and server or simultaneously acting as both client and server. Moreover, these nodes can operate in a heterogeneous fashion with respect to one another. In an alternate embodiment, the invention describes a mesh network comprised of nodes operating over TV white-space. The nodes of this white-space mesh network could, in alternate embodiments, operate in a heterogeneous fashion or could dynamically switch roles between client and server. These nodes could in alternate embodiments become multi access radio technology nodes. 
     This invention additionally discloses self-organizing network embodiments that can be implemented in the heterogeneous mesh networks or in a white-space mesh network. In the embodiments described herein, data within the network can become agnostic in terms of its protocol. As such, embodiments of the invention also include novel methods of monitoring operational parameters within a mesh network, adjusting those operational parameters, and creating and implementing routing tables. 
     In additional embodiments, this invention allows the creation of unique routing protocols, in part because of the agnostic nature of the data. These routing protocols can facilitate distributed computation of network topology and/or path determination. Specifically, when agnostic data are routed within the networks created herein, it is possible to use the transmission capabilities of the multi access radio technologies for data generated from, or destined to, a wide variety of radio communication protocols, frequencies, duplexing schemes, and the like. Accordingly, additional embodiments of the present invention include methods of routing data within a heterogeneous mesh network. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is an illustration of an example multi-RAT node for deployment within a mesh network. 
         FIG.  2    is an illustration of an example heterogeneous mesh network of the present invention. 
         FIG.  3    is an illustration of the architecture of select layers of a device used within a mesh network described in various embodiments herein. 
         FIG.  4    illustrates examples of routing protocols that can be used in various embodiments described herein. 
     
    
    
     DETAILED DESCRIPTION 
     The embodiments of this invention differ conceptually from prior art gateway paradigms because the custom designed layer stacks of this invention abstract the protocols that make each radio technology unique, thereby creating an agnostic data set that can be seamlessly routed throughout a wireless network. In other words, in the embodiments described herein, we have created an adaptation layer that spans all MAC layers so that we can bridge between heterogeneous access layers. In embodiments of this invention, individual nodes operating on different protocols, different frequencies, different hardware manifestations, or different duplexing schemes can be part of a dynamic mesh network. This dynamic mesh network uses a single routing table for heterogeneous nodes contained within the mesh network. 
     Mesh Networks 
     The term “mesh network” is typically defined as a network comprised of two or more nodes wherein the nodes act as routers. Illustratively, an online encyclopedia from PC Magazine defines a mesh network as follows: “(1) [a] network that relies on all nodes to propagate signals. Although the wireless signal may start at some base station (access point) attached to a wired network, a wireless mesh network extends the transmission distance by relaying the signal from one computer to another . . . . (2) A network that provides Wi-Fi connectivity within an urban or suburban environment. It comprises ‘mesh routers,’ which are a combination base station (access point) and router in one device. Also called ‘mesh nodes,’ they are typically installed on street light poles, from which they obtain their power.” PC Mag.com Encyclopedia, http://www.pcmag.com/encyclopedia/term/54776/wireless-mesh-network 
     Similarly, another online source states: mesh “networks rely on a series of nodes that transfer data wirelessly. Each node acts as an individual router, so the network can constantly reroute data to take advantage of the best pathways. It allows information to ‘hop’ from one node to another, circumventing blocked or broken paths in the network. Unlike other wireless networks, mesh networks use nodes that are all fully connected to one another, so the nodes are not mobile, but they can be easily configured to form ad hoc networks.” Power Source Online,  Mesh Networks,  Kristin Masters March 2010. http://www.powersourceonline.com/magazine/2010/03/mesh-networks 
     As used in this application, we define the term “dynamic mesh node” as a mesh node that is capable of playing a dynamic role within a network. A dynamic role could mean, by way of example, being capable of being a client with respect to one node and a server with respect to another node in the network. Dynamic can also mean switching radio access technologies. Prior art mesh nodes did not have the ability to play a dynamic role within a network. Rather, as can be seen from the above two definitions, mesh nodes acted as a base station access point and router. These roles were predetermined. The nodes within the mesh networks did not dynamically function as a client to one node, and a server to another, nor did they dynamically change transmit frequencies or protocols, for example. While mesh nodes and mesh networks are described herein, the inventors have contemplated the use of the techniques and methods disclosed herein with multi-RAT nodes that are not mesh nodes, for example, wherein the multi-RAT nodes are connected to at least one common network allowing for point-to-point communication. 
     Multiple Radio Access Technology (“multi-RAT”) Nodes 
     The concept of multiple radio access technology will also be defined. The term “radio access technology” indicates the type of radio technology used to access a core network. Multiple radio access technology, or multi-RAT, is a radio technology capable of operating in varying parameters. These varying radio parameters could be, for example, different protocols, different duplexing schemes, wired versus wireless, disparate frequency bands, and the like. 
     By disparate frequency bands, we mean different frequency ranges, or, frequencies from different categories of standards, or from generally accepted frequency ranges for a given technology. For example, the Wi-Fi protocol standard is currently authorized for use at two different frequencies in the United States, 5 GHz according to the 802.1a standard and 2.4 GHz according to the 802.1b standard. However, the message format, media access method, etc. are identical regardless of the frequency used. Thus, in our lexicography, a device that could communicate using Wi-Fi at both 5 GHz and 2.4 GHz would not be a multi-RAT device or node because both of these frequencies are considered within the art to represent instances of the Wi-Fi protocol. An example of a radio capable of operating in disparate frequency bands would be a radio that could work in a Wi-Fi band of either 2.4 GHz or 5 GHz and that same radio could also operate at 700 MHz or any other cellular frequency band, which requires a different media access method and/or a different message format. This type of a radio is an example of a multi-RAT node. 
     Similarly, we use the term “heterogeneous mesh network” to mean at least two nodes capable of: using different protocols, or different duplexing schemes, or operating in disparate frequency bands, or using different transmit/receive mediums, such as wired versus wireless. Different protocols may include Wi-Fi, 2G, 3G, 4G, 5G, WCDMA, LTE, LTE Advanced, ZigBee, or Bluetooth. Different duplexing schemes may include time division, code division, and frequency division schemes. Disparate frequency bands may include so-called “whitespace,” VHF and UHF channels, cellular telephony bands, public safety bands, and the like. 
     A multi-RAT node may include one or more “Gs,” including 2G, 3G, 4G, 5G and Wi-Fi. Where the present disclosure mentions any RAT, such as 2G/3G/4G/5G/Wi-Fi, it is understood that any other RAT could be substituted. E.g., any combination of 2 RATs, any combination of 3 RATs, etc. is enabled by the present disclosure; interworking between any 2 RATs is enabled by the present disclosure; virtualization of any RAT at the core (stand-alone or non-standalone) or at the RAN to appear as another RAT is enabled by the present disclosure; changing of operational parameters of any RAT based on environment variables of any RAT is contemplated; addition of one or more additional RF chains is contemplated, in some embodiments, to support the processing requirements of any particular RAT, which in combination with the multi-RAT architecture disclosed herein enables a multi-RAT node with any combination of RATs. 
     The multi-RAT nodes of the present invention have hardware, firmware, and software aspects. Focusing first on the hardware aspects,  FIG.  1    shows hardware that could be used in embodiments of this invention. In an embodiment, a multi-RAT node  100  is comprised of at least one processor  110 , access hardware  120 , backhaul hardware  130 , an RF front-end  140 , and a timing source  150 . By way of example, the at least one processor  110  could contain firmware written in Linux. Additionally, the RF front-end  140  can be configured to provide RF capabilities for multiple radio access technologies. 
     In one embodiment, the timing source could be GPS. Alternatively, the timing source could be derived from the Ethernet, or an IEEE 1588 source, such as SyncE, PTP/1588v2, and the like. In an alternate embodiment, wherein one multi-RAT node  100  may have access to GPS time, but another multi-RAT node  100  may be indoors, the two multi-RAT nodes  100  could use differential time synching techniques well known to those of skill in the art so that the indoor multi-RAT node  100  could sync its timing with that of the outdoor multi-RAT node  100 . In another embodiment, the multi-RAT node  100  could be a dynamic multi-RAT node. 
     In alternate embodiments, the at least one processor  110 , could be broken down into an access processor  112 , a backhaul processor  114 , a common processor  116 , or any combination thereof. In this embodiment, the access hardware  120  is coupled to the at least one processor  110 . In an alternate embodiment, having a separate access processor  112 , the access hardware  120  could be coupled to the access processor  112 , to the at least one processor  110 , or to the common processor  116 , or any combination thereof. Similarly, in another alternate embodiment, having a separate backhaul processor  114 , the backhaul hardware  130  could be coupled to the backhaul processor  114 , to the common processor  110 , or to the common processor  116 , or any combination thereof. 
     Those skilled in the art will appreciate that access and backhaul hardware will vary depending on the access or backhaul protocol or frequency being used to perform access or backhaul. By way of example, if a particular multi-RAT node  100  was designed to perform access on LTE and Wi-Fi, it could have the radio access technology components that would perform access on these two different protocols. For LTE access, the access hardware  120  could be comprised of: a baseband processor and CPU cores for the firmware. The baseband processor could generate digital RF signals, which are modulated by the RF front end  140 . These processors could be connected to the RF front end  140  via common public radio interfaces. Alternatively, some or all of the necessary radio access technology may incorporate Commercial Off-the-Shelf (COTS) hardware/firmware devices, such as conventional Wi-Fi access hardware based on Atheros chips with embedded firmware and one or more external antennas. 
     Those skilled in the art will recognize that multiple hardware configurations could be used depending upon the access protocol, backhaul protocol, duplexing scheme, or operating frequency band by adding or replacing daughter cards to the dynamic multi-RAT node  100 . Presently, there are off-the-shelf radio cards that can be used for the varying radio parameters. Accordingly, the multi-RAT nodes  100  of the present invention could be designed to contain as many radio cards as desired given the radio parameters of heterogeneous mesh networks within which the multi-RAT node  100  is likely to operate. Those of skill in the art will recognize that, to the extent an off-the shelf radio card is not available to accomplish transmission/reception in a particular radio parameter, a radio card capable of performing, e.g., in white space frequencies, would not be difficult to design. 
     Similarly, in the present invention, we describe how to make and use the inventions operating within well-known industry protocols. To the extent that additional protocols are adopted in the future, the teachings herein would be equally applicable. Additionally, if a person of skill in the art were to modify an already known protocol, such as LTE, and make it into a proprietary LTE protocol, for example, the teachings of this patent application would be equally applicable; and embodiments described herein could be adapted to accommodate this proprietary protocol. 
     Self-Organizing Network “SON” 
     Those of skill in the art will recognize that the term “SON” is a frequently used concept, but one that is devoid of a standard way of implementing the principles of self-organization that the moniker implies. As a result, SON embodies principles of self-organization, typically performed by those skilled in the art using proprietary architecture. Given that there are no true heterogeneous mesh networks to date, SON functionality, naturally, is being implemented on homogeneous networks. 
     In the present invention, because most of the mesh networks described herein are heterogeneous, it follows naturally that any SON implementations would be able to operate in a heterogeneous network. Against this backdrop, we use the term “SON” throughout this application to mean the traditional functionality of SON, i.e., self-organization, self-optimization, auto-configuration, self-healing, and the like, applied on a heterogeneous network as that term is used throughout this patent application. The SON principles described herein could also be used on the white-space embodiments discussed infra. 
     For illustrative purposes, we will describe SON functionality in an exemplary wireless mesh network  200  shown in  FIG.  2   . In this embodiment, multi-RAT node  210  is providing access on LTE, multi-RAT node  220  is providing access on Wi-Fi, and multi-RAT node  230  is providing access on 3G. In this embodiment, the multi-RAT nodes  210 ,  220 ,  230  could be using Wi-Fi backhaul. As such, this network  200  is a heterogeneous mesh network. In this heterogeneous mesh network, multi-RAT node  230  has a wired connection  235  to a computing cloud  240 . Multi-RAT node  230  has a wireless connection  225  to multi-RAT node  220  and a wireless connection  217  to multi-RAT node  210 . Additionally, multi-RAT node  220  has a wireless connection  215  to multi-RAT node  210 . These connections are exemplary and could be altered in alternate embodiments. Additionally, heterogeneous mesh networks of the present invention could include more or less than the three exemplary multi-RAT nodes pictured in  FIG.  2   . 
     The SON architecture, discussed more fully with reference to  FIG.  3   , is distributed between a computing cloud  240  and the multi-RAT nodes  210 ,  220 ,  230 . In one embodiment of SON functionality, the computing cloud  240  queries the multi-RAT nodes  210 ,  220 ,  230  regarding environmental conditions, e.g., interference, capacity, spectrum efficiency, routing path, network congestion, and the like. The multi-RAT nodes  210 ,  220 ,  230  respond by sending the requested parameters to the computing cloud  240 . The computing cloud  240  processes these responses so that it can instruct the multi-RAT nodes  210 ,  220 ,  230  to change an operational parameter thereby better optimizing the performance of the heterogeneous mesh network  200 . In these embodiments, operational parameters could be power level, channel, frequency band, spectrum reuse, as well as access, backhaul, client, or server, or routing paths. 
     In these embodiments, it is possible for a multi-RAT node  210 ,  220 , or  230  to change an operational parameters because of the custom designed architecture  300  described infra. For illustrative purposes only, in one situation, the computing cloud  240  may determine that the heterogeneous mesh network  200  is experiencing interference. In response, the computing cloud  240  may instruct multi-RAT nodes  210  and  230  to reduce their power output. 
     In another embodiment, the multi-RAT nodes  210 ,  220 , or  230  can also make decisions independent of the computing cloud  240  regarding whether to change an operational parameter because they also have custom designed architecture  300 . In one of these embodiments, for example, the multi-RAT nodes  210 ,  220 , or  230  could be pre-authorized to change channels if a certain interference threshold is crossed. Multi-RAT nodes could also contain the intelligence within their custom designed architecture  300  to be able to coordinate a handoff between them if one of their users is beginning to move into an area that would be better served by one of the other nodes in the network. 
     In another SON scenario, multi-RAT node  210  may be using its Wi-Fi radio for access and its LTE radio for backhaul. The computing cloud  240  may determine that multi-RAT node  210  is experiencing a backlog on the access side and that it could increase its efficiency by taking advantage of the greater downlink capacity built into the LTE standard. The computing cloud  240  could therefore instruct multi-RAT node  210  to dynamically switch roles, i.e., the LTE radio in multi-RAT node  210  should be used for backhaul and the Wi-Fi radio in multi-RAT node  210  should be used for access. 
     In similar embodiments, the computing cloud  240  could provide additional floating spectrum to one or more of the multi-RAT nodes  210 ,  220 , or  230  to increase network capacity, to adhere to QoS requirement, to efficiently reuse spectrum, and the like. 
     In another embodiment, two multi-RAT nodes  210 ,  220 , or  230  may be operating within close proximity to one another. For illustrative purposes, assume node  210  was servicing Verizon customers and node  220  was servicing AT&amp;T customers. If multi-RAT node  210  reached a pre-determined capacity threshold, it could coordinate with multi-RAT node  220  to hand off some of its Verizon customers, who are operating in a different frequency band, to multi-RAT node  220 . Multi-RAT node  220  could then provide service to customers of both Verizon and AT&amp;T on two different frequency bands. Some of the criteria that could be used to determine if this type of frequency shifting among the multi-RAT nodes  210 ,  220 , or  230  should occur are: (1) resource loads, e.g., DSP power, getting busy on one node; (2) one node may have better external resources, e.g., back-up power, wired backhaul, greater antenna height, optimum direction of antenna for a given coverage zone, and the like; and (3) similar key performance indicators that are well known in the art. 
     In this embodiment, once multi-RAT node  220  has been provisioned to provide services on two different frequencies, it must coordinate with multi-RAT node  210  by sharing information such as, traffic details, call details, RF quality measurements, and so forth. These nodes  210  and  220 , which could be two or could be many, can add or remove frequency bands and can coordinate with each other to force user equipment handoffs to accommodate the change in the frequency scheme. In an alternate embodiment, the computing cloud  240  could manage the transfer of some Verizon customers to a multi-RAT node. 
     In another embodiment of this invention, a multi-RAT node  210 ,  220 , or  230  may employ a method of increasing capacity by reducing its output power output thereby taking advantage of spectral reuse. In this embodiment, a multi-RAT node  210 , for example, monitors its capacity. When it begins to reach a maximum capacity threshold, it could request permission from the computing cloud  240  to decrease its power output, thereby increasing capacity. Upon receiving this request, the computing cloud  240  could determine whether to grant the request. Some of the factors that the computing cloud  240  could take into consideration when making this determination are radio bearer utilization, QoS, operator policies, and capacity considerations of other multi-RAT nodes in the mesh network. 
     In this embodiment, once the computing cloud  240  reaches a decision regarding the request to decrease power, the computing cloud  240  informs the multi-RAT node  210  of its decision. If the request if granted, the computing cloud  240  directs the multi-RAT node  210  to prepare to handoff any UE sessions that will be in a coverage gap once it reduces its output power. Optionally, the multi-RAT node  210  could query UE on its network to obtain measurement reports of other multi-RAT nodes  220  or  230 , for example, who may be able to absorb part of the coverage gap. In this embodiment, the multi-RAT node  210  could provide this information to the computing cloud  240 . 
     Once the computing cloud  240  has directed the multi-RAT node  210  to prepare to handoff some UEs, it then directs one or more selected multi-RAT nodes  220  or  230  to increase its/their power, thereby increasing coverage. After the instructed multi-RAT node  220  or  230  has increased its power, it may update virtualization manager data with radio bearer capacity reduction information. The multi-RAT node  220  or  230  could then send the updated virtualization manager to computing cloud  240 . After receiving this information, the computing cloud  240  virtualization manager may then direct the requesting multi-RAT node  210  to gracefully handoff in-progress UE sessions to other available multi-RAT nodes  220  or  230  in its neighborhood. Once the handoffs are completed, the requesting multi-RAT node  210  reduces its power to provide more capacity to UEs in its network. Optionally, this multi-RAT node  210  may update the virtualization manager with the resulting radio bearer capacity increase information and provide the updated virtualization manager to computing cloud  240 . 
     In another embodiment of the present invention, a multi-RAT node  210 ,  220 , or  230  in a mesh network may employ a method of increasing its coverage area by, for example, increasing power output. In this embodiment, a multi-RAT node  210  for example may monitor at least one network parameter and determine that a neighboring multi-RAT node  220  or  230  has ceased to function properly. After making this determination, the multi-RAT node  210  may contact the computing cloud  240  to report the malfunctioning multi-RAT node  220  or  230 . The computing cloud  240  may then analyze the radio bearer utilization, QoS, operator policies and capacity considerations of other multi-RAT nodes  220  or  230  in the mesh. Using its measurements and internal logic, the computing cloud  240  could then determine if any of the multi-RAT nodes  220  or  230  within the mesh network can increase power output to provide more coverage. 
     In another embodiment, one of the multi-RAT nodes  210 ,  220 , or  230  may, for example, be malfunctioning. In this embodiment, the computing cloud  240  could determine if one or more of the other multi-RAT nodes is able to fill the coverage gap caused by the malfunctioning node. The computing cloud  240  could coordinate with the functioning multi-RAT nodes so that at least one of them increases power, thereby extending coverage. After the coverage area has been extended, the multi-RAT nodes  210 ,  220 , or  230  may update the virtualization manager with the resulting radio bearer capacity reduction information. Additionally, in this embodiment, the multi-RAT node(s)  210 ,  220 , or  230  may have to handoff UE sessions in progress gracefully to other neighboring multi-RAT nodes in order to effectively extend coverage. 
     In alternate embodiments of this method, multi-RAT nodes may  210 ,  220 , or  230  dynamically increase the transmit power of a single sector or multiple sector radio bearer based, for example, on Signal-to-Noise Ratio (SNR) reports and/or location determination. This power adjustment may be performed in coordination with neighboring multi-RAT nodes, who correspondingly decrease their transmit power of the single sector or multiple sector radio bearer. A multi-RAT node  210 ,  220 , or  230  may perform this functionality by directly communicating with neighboring multi-RAT nodes or in coordination with the computing cloud  240 . 
     In an alternate embodiment, the multi-RAT nodes  210 ,  220 , and  230  could operate on white-space frequencies. As those of skill in the art will recognize, using white-space frequencies for communication requires flexibility in terms of pre-selecting an operational frequency so as to avoid interference with other white-space devices. Because the white-space spectrum is unlicensed, it must be shared among potential users. In this embodiment, the multi-RAT nodes  210 ,  220 , and  230  could use spectrum sensing techniques to determine which portion of the white-space spectrum is available for use. In an alternate embodiment, the multi-RAT nodes  220 ,  220 , and  230  could query a database containing frequency availability based on location, time, and the like. This database could be stored within any or all of the multi-RAT nodes  210 ,  220 , and  230 , in the computing cloud  240 , or in a remote location. 
       FIG.  3    shows a custom designed architecture  300  that can be used in embodiments of the heterogeneous mesh networks of this invention. Specifically, the custom designed architecture  300  of these embodiments builds upon the well-known Layer 1, Layer 2, Layer 3, Control Layer, Application Layer, and Management Layer architecture of the prior art. 
     In our custom designed architecture  300 , we add an abstraction layer  340 , a SON module  330 , and in addition add customizations to the other modules so that they can interoperate with the abstraction layer  340  and the SON module  330 . Specifically, our custom designed architecture  300  includes a management layer  380 , an application layer  310 , a control layer  320 , and an abstraction layer  340 . The abstraction layer  340  is communicatively coupled to at least one radio. For example, the embodiment of  FIG.  3    shows three multi access technology radios. One of these radios is an LTE radio  370 . One is a Wi-Fi radio  360 . And the third is radio technology X  350 . Once there are at least two radio access technologies within a single node, the node becomes a multi-RAT node as described herein. As can be seen from  FIG.  3   , additional radios  350  could be added to create multi-RAT nodes having X number of access technologies. 
     The abstraction layer  340  provides a common API interface to the layers above it. The abstraction layer  340  receives data from each of the radios beneath it and converts those data into protocol agnostic data. In some embodiments of the present invention, the SON module  330  interfaces with the SON portion of a computing cloud  240  in order to perform network optimization. 
     In terms of customization of the modules within the control layer  320 , the traffic control module  325  has the flexibility to create data queues based on priority without regard to radio access technology. The automatic neighbor relation management module  326  acts as an interface between the multiple radio access technologies so that neighbors within a particular mesh network become aware of the various resources provided by each node within the network. 
     In some embodiments, the power management module  324  and/or the radio resource management module  322  can interface with the SON module  330  to increase or decrease power, to change channels, and the like in order to optimize network operating conditions. 
     For illustration, assume that the custom designed architecture  300  was operational on a multi-RAT node having two radio technologies, LTE  370  and Wi-Fi  360 . In this embodiment, data could be received through the LTE radio  370 . These data would be received in Layer 1 of the LTE radio  370 . They would proceed up through Layer 2 and Layer 3 to the abstraction layer  340 . The abstraction layer  340  would abstract the LTE-specific information from the data packet and would send a protocol agnostic data stream to the control layer  320 . The control layer  320  would then decide the routing, which in this case could be through either the LTE radio  370  or the Wi-Fi radio  360 . In embodiments of the present invention, multi-RAT nodes use and create distributed routing protocols that perform L2 bridging through an abstraction layer. 
     Additional embodiments of the present invention include novel routing protocols. In the prior art, routing was coupled to a specific operational parameter, e.g., protocol, duplexing scheme, wired versus wireless, or frequency band. In the present invention, routing is not tethered to these operational parameters because multi-RAT nodes participate within a mesh network with disparate operational parameters. The abstraction layer  340 , in essence, creates agnostic data packets that can be routed through any of the multi-RAT nodes within a given heterogeneous mesh network. 
     In prior art mesh networks, nodes typically connected to adjacent peers. Referring to  FIG.  2   , adjacent peers could be  210  and  220 , connected wireless via  215 , and  220  and  230 , connected wirelessly via  225 . In embodiments of this invention, the nodes within a heterogeneous mesh network can have multiple connections such as multi-RAT node  230 , which can connect to multi-RAT node  210  via connection pathways  225  and  215  or via connection pathway  217 . In alternate embodiments of a heterogeneous mesh network, there could be more than three nodes as pictured in  FIG.  2   . In these embodiments, nodes that have multiple backhaul connections, e.g., multi-RAT node  230 , could make dynamic decisions about the most effective connection paths for it to use at any given time. These decisions could be based on any of the environmental conditions discussed herein including, but not limited to interference, capacity, spectrum efficiency, routing path, network congestion, spectral reuse, throughput, latency, coverage gaps, signal-to-noise ratio, quality-of-service, spectral sensing for white space use, and the like. 
     In additional embodiments, this invention allows the creation of unique routing protocols, in part because of the agnostic nature of the data. These routing protocols can facilitate distributed computation of network topology and/or path determination. Specifically, when agnostic data are routed within the networks created herein, it is possible to use the transmission capabilities of the multi access radio technologies for data generated from, or destined to, a wide variety of radio communication protocols, frequencies, duplexing schemes, and the like. These routing protocols may route data transparently across RATs, at the multi-RAT node or via a cloud server or centralized network node, in some embodiments. 
       FIG.  4    illustrates the concept of the mesh routing protocols in these embodiments.  FIG.  4    depicts two multi-RAT nodes  410  and  420 . In this exemplary embodiment, multi-RAT node  410  can operate on LTE and Wi-Fi, while multi-RAT node  420  operates over LTE, Wi-Fi, and 3G. When the multi-RAT nodes  410  and  420  exchange the mesh routing protocols, multi-RAT node  410  may place LTE data as priority 1 and Wi-Fi data as priority 2. 
     For purposes of illustration, we assume that, according to the current mesh routing table, multi-RAT node  420  acts as a relay node for multi-RAT node  410 . In this example, multi-RAT node  410  transmits a data stream  430  containing data packets having different radio parameters. For example, data packets could be priority 1 data packets  432 , LTE in this example, and priority 2 data packets  434 , Wi-Fi in this example. When this data stream  430  is received at multi-RAT node  420 , the packets within the data stream  420  retain their priority, but they are agnostic in terms of their radio parameters. 
     In a traditional mesh network, all of the multi-RAT nodes would have had the same radio parameters. Accordingly, when a routing node received a data stream, it would retransmit the packets on the same radio type as that of its neighbor, who originally transmitted the data packet. In the heterogeneous mesh network of the present invention, the multi-RAT nodes contained therein are capable of transmitting and receiving in a heterogeneous fashion. As such, multi-RAT node  420  can relay these data packets on any of its three available radio technologies, i.e., LTE, Wi-Fi, or 3G. 
     In this embodiment, a traffic control module  325  receives these data packets and provides a priority indicator to each of the packets within the data stream  430 . The SON module  330  stored within multi-RAT node  420 , or in alternate embodiments stored within the computing cloud  240 , could queue these data packets to be retransmitted according to the priority that has been ascribed to each specific data packet. Specifically, when multi-RAT node  420  receives data stream  430 , it can utilize all three of its radio access technologies for retransmitting the data stream  430 . In one embodiment, multi-RAT node  420  could use its LTE radio transmit channel  440  for transmitting priority 1 data packets. It could use its 3G radio transmit channel  460  for transmitting priority 2 data packets. And it could divide the resources available from its Wi-Fi radio transmit channel  450  to transmit both priority 1 and priority 2 data packets. 
     This allocation of resources is fluid and is a function of time and network congestion, which is an environmental condition. If at a later point in time, priority 1 data packets became backlogged, the SON module  330  could alter an operational parameter such as using the 3G radio transmit channel  460  to transmit priority 1 data and maintaining the Wi-Fi transmit channel  450  as a shared resource for transmitting both priority 1 and priority 2 data. 
     Those of skill in the art will recognize that these radio resources could be used numerous different ways depending open things such as Quality of Service requirements including constraints on throughput and/or delay, subscriber agreements, network capacity, data congestion, efficient use of spectrum, and the like. Moreover, routing decisions could be made based upon environmental conditions such as: interference, capacity, spectrum efficiency, routing path, network congestion, spectral reuse, throughput, latency, coverage gaps, signal-to-noise ratio, quality-of-service, spectral sensing for white space use, and the like. Skilled artisans will also recognize that these decisions could be made by multi-RAT nodes, the computing cloud, or jointly between these devices. 
     The foregoing discussion discloses and describes merely exemplary embodiments of the present invention. As will be understood by those skilled in the art, the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. Various components in the devices described herein may be added, removed, or substituted with those having the same or similar functionality. Various steps as described in the figures and specification may be added or removed from the processes described herein, and the steps described may be performed in an alternative order, consistent with the spirit of the invention. Features of one embodiment can be provided in conjunction with features of another embodiment. Accordingly, the disclosure of the present invention is intended to be illustrative, but not limiting of the scope of the invention, as well as other claims. The disclosure, including any readily discernible variants of the teachings herein, defines, in part, the scope of the foregoing claim terminology.