Cognitive Hotspot Technology (CHT)


Access to wireless networks is customer-oriented. That means that the client decides where and when to connect to the network. It is also the logic of the client terminal (STA). It decides autonomously which Access Point (AP) best serves its purposes. Wireless Local Areal Networks (WLANs) are governed by the IEEE (Institute of Electrical and Electronic Engineers) 802.11 standard. Released at the late 90s, it allowed substituting Ethernet wired communications with the well-known WiFi technology. Without the periodic amendments known as 802.11g, 802.11n, and the newer 802.11ac, it would have been out of date in a few years. Fortunately, WiFi networks enjoy better health than ever before, thanks in part to the use of unlicensed spectrum and how cheap and efficient it is to deploy them. And the future is even more promising, thanks to the improvements in the standard that are being proposed at this time.

“Fortunately, WiFi Networks enjoy better health than ever before, thanks in part to the user of unlicensed spectrum and how cheap and efficient it is to deploy them”

However, in this protocol, there is no mechanism that allows the network to decide which AP is the most adequate to serve traffic to a STA. This is one of the lacks of the 802.11 standards: basic devices are not supposed to share information and act in a coordinated way. Without modifications like the ones proposed at Galgus patented technology, the STAs and APs work independently, wasting system resources such as bandwidth, airtime, and transmitted power. Our CHT (Cognitive Hotspot Technology) greatly increases network performance in a clean and elegant way, by allowing APs to measure the radio characteristics of their environment, to share information, and to make smart decisions together, without the need for a master controller.

Cognitive Hotspot Technology (CHT)

CHT is a fully-distributed technology, thereby avoiding the drawbacks and weaknesses of current centralized networks, such as failure of critical nodes (central control nodes) and bottlenecks. Furthermore, CHT has been designed to be a multi-platform technology that can be embedded in access points of any manufacturer.

“CHT converts regular APs into cognitive APs, which are aware of their environment”

CHT converts regular APs into cognitive APs, which are aware of their environment. They proceed continuously sensing the environment to adapt to it. Cognitive APs exchanges information with neighboring APs, managing available resources jointly.

Our software technology is a compound of many different modules, each one in charge of optimizing a specific management task. For example, CHT has specific modules for smart roaming, distributed communications, load balancing, automatic failure recovery, automatic node discovery, automatic channel assignment, advanced security, traffic congestion management, and interference minimization.

CHT is a software product that provides APs with cognitive capabilities, allowing them to sense its environment, exchange information with neighboring WAPs and cooperate between them to ensure efficient use of network resources. It implements a set of features, which, based on its cognitive capabilities, enhance user experience.

CHT paradigm for distributed smart network management.

CHT is composed on the following proprietary algorithms:

  • Smart Roaming (SR), for soft handover of users between neighboring APs.
  • Automatic Channel Assignment (ACA), for selecting the best suitable spectrum on 2.4 Ghz and 5 Ghz bands.
  • Advanced Load Balancing (ALB), to manage the ever-changing demand of users between APs.
  • Interference Minimizer (IM), to mitigate interference between neighboring APs while covering all the users.
  • Additional features like congestion management, self-configuration, location-based services, self-healing, automatic failure recovery, security, etc.

Forget the Throughput: Improve the Goodput!

CHT (Cognitive HotspotTM Technology) is an embedded software product that provides the Access Points (APs) with cognitive capabilities, allowing it to sense its environment, exchange information with neighboring APs and cooperate between them to ensure an efficient use of wireless resources. CHT implements a set of functions, which, based on its cognitive capabilities, enhance user experience. As a result, CHT raises spectral efficiency and also improves Goodput up to 400 % (the data rate of successfully delivered packets).

Goodput performance versus the number of clients using only one dual-radio AP.

In any wireless data transmission, a portion of the data will not be delivered to the users due to interferences, congestion, packet collisions, etc. The undelivered data rate is referred to as “Badput” while the successfully delivered portion of the data rate is called “Goodput”. It is considered that a satisfying multimedia service cannot be given if Goodput falls below 97.5%. CHT continuously assesses and optimizes network load and interference levels in real-time to maximize performance and minimize interference. Experiments show that, when all clients decide to connect to the same radio, APs are not able to serve traffic properly to more than 18 clients (2.4 Ghz), or 36 clients (5 Ghz).

“When equipped with CHT, a single AP can maintain up to 90 simultaneous clients”

However, when equipped with CHT, a single AP can maintain up to 90 simultaneous clients requesting a 1Mbps videostream without falling below 97.5% of Goodput. The same AP without CHT and only one active radio may start struggling after just 18 clients connected. Even with both radios active in the absence of CHT, after 53 users connected, performance shall degrade dramatically due to poor interference optimization and no radio balance.

Key features

  • EEE 802.11ac compliant and backward compatible to 802.11a/b/g/n.
  • Variable emission power/channel selection to minimize interferences.
  • Optimal distribution of clients among APs.
  • Distributed technology guarantees seamless operation in case of failure.
  • Enhanced features provided by CHT.
  • Powerful management and analytics tools provided by CHT Manager.

Smart Roaming (SR)

Smart Roaming (SR) allows transferring users from one AP to another when their SNIR (Signal-To-Noise-and-Interference) falls below a minimum threshold. This minimum threshold is defined as a value that guarantees enough throughput and therefore QoS (Quality of Service) for every client. The user is only roamed in case there is another AP that offers better SNIR to this client. With SR, access points decide to which node a certain user will connect. This is a transparent process since decisions are made by APs and not the user device. If the conditions change, or if the user changes its location, CHT will act in real-time, switching the user to a different access point.

Advanced Load Balancing (ALB)

Load Balancing (LB) allows distributing connected users between the 2 radios of AP, one in 2.4GHz and the other one in 5GHz frequency bands (Intra-AP Load Balancing). Furthermore, Load Balancing distributes connected users among different APs in the network, ensuring there are no bottlenecks (Inter-AP Load Balancing). In this manner, each AP provides service to an optimum number of users, reducing network congestion. The distribution takes into account the type of application that the client is using (streaming, web browsing, etc.), ensuring a high quality of service at all times.

Comparison of user distribution with (right) and without (left) CHT Advanced Load Balancing feature.

Traffic Congestion Management (TCM)

Traffic Congestion Management (TCM) is a mechanism that can identify problematic users who are making an excessive use of the available network capacity. To solve this issue, TCM measures and set limits to control the transmission speed of the problematic client in real-time, ensuring that network resources are fairly shared. TCM acts at wireless level preventing less effective TCP congestion mechanism to trigger and improving overall network performance including wire and wireless networks.

Traffic peaks can be detected and analyzed within CHT Manager.

 Band Steering (BS)

Band steering is used to distribute clients’ stations between the 2.4GHz frequency band and the 5GHz frequency band depending on the channel occupancy at each band. This is very useful in current Wi-Fi networks due to the saturation of the 2.4GHz frequency band, which is also used by other technologies like Bluetooth, very crowded due to the rising of IoT.

Band Steering with only one AP. Clients are properly distributed among the available radios.

Automatic Channel Assignment (ACA)

Automatic Channel Assignment (ACA) is a feature that automatically and dynamically assigns transmission channels to a group of APs, selecting the channel configuration that reduces to the minimum level of interference in the network and therefore increases overall throughput. It works continuously, reacting to any changes in the environment, such as the activation of an additional access point internal or external ones. As conditions constantly change, suddenly our perfectly configured network doesn’t work as expected. With CHT, APs detect the interference source (WiFi or non-WiFi) and recalculate the new optimum channel assignment.

Mean and standard deviation of interference (mW) in wireless networks, with and without different versions of ACA algorithms.


Galgus manufactures smart WiFi solutions. We develop technology that enables performance improvement of high-density 802.11 networks, reducing the noise level in the environment, and promoting a more efficient and responsible use of resources.

With its recognized CHT (Cognitive HotspotTM Technology), Galgus provides to various vertical markets a complete solution that solves the main challenges that WiFi networks are facing nowadays. Among the main benefits of our patented technology, we shall highlight that CHT increases network capacity, reduces interference, prevents congestion and slow data rates, reduces EMIs (Electro-Magnetic Interference) to critical systems, and enables automatic configuration / automatic failure detection and recovery.

Galgus is boosting wireless performance in all possible WiFi scenarios thanks to CHT. Our APs are equipped with the latest technology, which together with the benefits of CHT will make your WiFi network perform better than ever, even in the most challenging situations.

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