Array OS

Network edge intelligence

Conventional Wi-Fi networks use thin APs connected to a centralized controller. These thin APs are dependent on the controller to make authentication, policy, RF, and sometimes packet processing decisions for them. The dependency of APs on the controller creates a single point of failure – if the controller fails, the entire wireless network connected to that controller goes out.

With ArrayOS functioning independently on each Array, the Arrays themselves make all controlling decisions at the edge of the network. With each Array operating autonomously, there is no single point of failure in the network. Additionally, the ArrayOS monitors all Array functions locally and can apply policy and RF design decisions immediately and efficiently instead of being dependent on communication back to a central control point.

Radio optimization

The multi-radio and directional antenna design of our Wireless Arrays provide significantly greater control of RF design and management compared to traditional APs. All radio resources can be individually controlled for band selection (2.4GHz or 5GHz), transmit power, and channel allocation. Control can be done either automatically or manually.

Each radio within the Wireless Array can be set to operate in either 2.4GHz or 5GHz, allowing the design to match client types today and adapt in the future as needed. This contrasts to thin APs which are fixed in design with one radio in 2.4GHz, one in 5GHz, and no flexibility to change based on client requirements.

We also support Auto Channel per Array, which provides an automatic means of allocating Wi-Fi channels between radios across all Arrays in a deployment. Proper channel design is essential to ensure best system performance since interference from Wi-Fi or non-Wi-Fi systems on a given channel of operation will degrade user experience. Auto Channel scans the RF environment on a radio-by-radio basis, coordinated among all Arrays in the network, to determine the best channel of operation per radio.

For transmit power control, each Array supports Auto Cell – an automatic, self-tuning mechanism that balances cell size between Arrays. It ensures sufficient coverage while limiting the RF energy that would extend beyond the organizational boundary between Arrays. This helps to minimize potential interference with neighboring networks and allows for automatic detection and coverage expansion to compensate for gaps caused by system interruptions.

Resource assurance

The distributed design of the Array provides a level of processing power and intelligence not available in traditional thin AP designs where much of the resources reside in a centralized controller. By placing these resources at the network edge, the Array can apply proactive and pre-emptive monitoring of operational resources to detect and respond to issues when they occur.

Station Assurance continuously monitors wireless client behavior for potential issues. If a client is detected encountering connectivity or performance issues, a notification is logged enabling the network administrator to respond to the issue proactively before the end-user complains. Among the elements monitored are authentication failures, packet error rates, packet retry rates, data rates, signal strength, and signal to noise ratio.

Radio Assurance executes local testing of Array radio resources and self-healing to ensure wireless service availability. The monitor radio periodically functions as a wireless client and connects to each of the user servicing radios in the Array. If a problem is detected, multiple options for action may be taken, including logging a notification or resetting the radio itself.

Network Assurance actively monitors the status of key network elements, including the Gateway, RADIUS servers, NTP servers, SNMP trap hosts, and DNS servers. If any of these elements are unreachable, a notification is logged via syslog. The Array can be optionally configured to disassociated users proactively if network resources are not available so that clients do not remain connected wirelessly but with no network service.

Device optimization

The multi-radio architecture of the Array provides a high level of flexibility in allocating Wi-Fi users and devices among system resources to optimize overall performance. As wireless is a shared communications medium, clients on a given radio resource affect the performance of others using the same resource.

In the Array, Wi-Fi devices are identified by type upon connecting to the network (e.g. laptop, tablet, smartphone, gaming device). This information is then used to map the device to specific resources as desired.

Dedicated radios and wireless networks (SSIDs) can be assigned to devices that need high bandwidth or are operating in a specific mode, for example a keynote speaker at a convention with thousands of other wireless users in the audience. As another example, a collection of legacy scanners operating at slow 802.11b speeds can be dedicated to specific radio resources. These users would otherwise slow down the operation of faster 802.11g or 802.11n clients if they functioned on the same radios.

At a higher level, Station Load Balancing automatically distributes Wi-Fi devices across the multiple radios in an Array to optimize performance. Evenly distributed client load distribution ensures the best quality of experience for each user. By distributing the client there is better utilization of Array radio resources by ensuring more radios are servicing clients and not idle.

More reliable wireless

One of the biggest advantages of the Array architecture is the resiliency the solution provides to the wireless network. With dedicated hardware and software resources, each Array operates independently without the need for a centralized controller. Only network management, via the Xirrus Management System (XMS), is centralized on a Xirrus network however it is not required for operation.

With traditional enterprise wireless solutions, controller failure will bring down the entire wireless system connected to it creating a single point of failure. While redundant or n+1 resiliency can be implemented with these solutions, it comes at a steep price. With a Xirrus Array network, failure of one Array will impact only its service area, ensuring a much more reliable network without adding cost.

Better RF control

Through superior RF management, ArrayOS creates a more stable environment for Wi-Fi clients and enables higher performing wireless networks. Auto Channel and Auto Cell functions automatically create optimal RF coverage and configuration for maximum Wi-Fi performance without painstaking RF planning. Software configurable Wi-Fi band selection per modular AP allows wireless spectrum to be flexibly set to match the capabilities of clients in the network. And with independent transmit power control per radio, wireless signal level can be controlled for proper coverage on a sector by sector basis.

Altogether, much greater control of the RF environment is available in a Xirrus Array network compared to traditional solutions. This control provides the ability to optimize performance in challenging wireless environments, in particular where a high density of users exist such as schools, stadiums, and conference centers.

Proactive issue identification and resolution

With Resource Assurance Management, ArrayOS proactively monitors resources across the entire wireless network – including clients, network elements, and its own operation. This functionality is built into every Array and can function with or without centralized management. The distributed intelligence of the Array architecture enables this proactive and pre-emptive problem notification and resolution allowing Network Administrators to focus on other issues.

Optimized resource allocation

With multiple radios available in each Array, network resources can be more optimally allocated to meet particular deployment requirements and adapted as requirements change. Xirrus Arrays identify the type of device connecting to the network (e.g. laptop, tablet, smartphone, gaming device). Based on device type, specific policies can be applied such as bandwidth restrictions, application types, and time restrictions. By controlling the traffic for each device, the network administrator can ensure that no one device is hoarding the bandwidth and that only the proper network resources are being used. Resources can also be allocated based on device performance ensuring the performance of faster device types (e.g. 802.11n) are not negatively impacted by slower devices types (e.g. 802.11b).

Model specifications

x – total number of radios within the Xirrus Array Network

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