The best way to deploy a scalable wireless network is with a distributed architecture that joins multiple radios together to create greater capacity and support higher user density. This is how the cellular industry addressed capacity issues with their mobile networks in the late 1990’s. By placing more radios on each cell tower coupled with directional antennas, they created greater capacity and coverage per location. This enabled the industry to scale to keep up with demand while saving significant expense by not deploying many more cell towers.
Xirrus has applied this same approach to Wi-Fi. Our distributed, multi-radio solution delivers the most scalable wireless platform in the industry. It is easier to deploy, is more cost effective, and can grow as performance and capacity change.
Architectural Components
There are three primary components in the Xirrus Wireless Array
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Dense modular APs
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Directional antennas
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Distributed intelligence
Dense modular APs
Wi-Fi networks use a shared communications medium. Wireless bandwidth on a radio is shared amongst multiple devices connecting to that radio. The more devices connected, the less bandwidth available to each device.
To ensure sufficient bandwidth in today’s overloaded mobile device environment, more radios are required. While standard two radio APs scale to a certain level, there are limits to how many APs you can add in a given physical location to scale capacity. By incorporating 2 to 16 modular APs per Xirrus Array, we scale to much greater bandwidth to service more devices. This approach also provides significant savings by reducing the amount of equipment, cable drops, switch ports, and installation labor costs required in the network.
Directional antennas
National communications agencies limit the amount of energy a radio can transmit which restricts the coverage area of that radio. Conventional APs utilize omni-directional antennas to transmit wireless signal in a 360-degree pattern – similar to a light bulb.
Wireless Arrays utilize directional antennas to focus that same energy in a specific direction – similar to a flashlight – to provide greater range to the wireless signal. More importantly, the directional antennas help isolate radios within a given chassis to enable the multi-radio Array design.
Distributed intelligence
Traditional wireless architectures consist of thin APs connected to a central controller. The controller resides in the backend of the network and performs control, security and management functions for multiple (often hundreds) of APs. The primary issues with this approach are creation of a single point of failure and potential overload/congestion in the controller. In addition, the thin AP design approach limits the intelligence and processing power that can be applied at the edge of the network in each AP to recognize applications, shape traffic, or enforce security policies.
Xirrus integrates the controller function and application-level visibility control into each wireless Array and AP to distribute the intelligence, much like wired Ethernet switches. By distributing the network, you get better scalability, resiliency, and overall performance compared to centralized architectures. With greater compute power built into each Xirrus product compared to traditional APs, functions such as application-level visibility and control can be executed directly at the network edge instead of in a centralized controller or appliance in the core.
What it means to you
There are numerous advantages to our approach:
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Designed to scale up to very high capacity, not just basic wireless coverage
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Designed for the increasing device densities of BYOD, not just 10 people in a conference room
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Designed for multi-media and critical applications, not just email and web browsing
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Designed to optimize network performance and security by application, not just by user or device
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Designed to be adaptive and upgraded as requirements grow, not replaced as technology changes
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Designed to lower total cost of ownership by requiring less equipment and infrastructure, not more
The Xirrus Wireless Array platform enables superior functionality, capacity, and upgradability not possible with conventional AP offerings. We make it possible to communicate when and where it is most optimal for your workforce and your customers. By improving communications, you improve productivity and profitability.
The following critical technologies make it possible to meet the rapidly evolving requirements for a robust wireless network:
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Modular AP system
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Integrated controller
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Multi-sector antenna system
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Application control
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Access management
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Dedicated security monitoring
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Dedicated wireless backhaul
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Radio optimization management
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Resource assurance management
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Device optimization management
The exploding growth of smartphones, tablets and mobile devices is crashing today's wireless networks - mandating infrastructure upgrades. The normal approach has been to add more and more APs to grow wireless capacity, but this meant costly network changes and poor performance.
Adding wireless capacity requires adding more radios. Our multi-radio,modular AP platform approach provides a unique, high performance wireless solution which can adapt to meet new requirements as your needs change. The Wireless Arrays allow you to:
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Add radios to an Array chassis to increase capacity
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Reposition radios within a chassis to optimize RF coverage patterns
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Migrate radios and users from 2.4GHz to higher performing 5GHz band when ready (all radios are multi-band)
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Swap radios to higher performing wireless technology as available (802.11ac and 802.11ad standard)
The flexibility provided by the Wireless Array enables capacity planning without replacement of the Array chassis itself. This ensures a long product lifespan (5+ years) that is adaptive to your business requirements and protects your investment against inevitable increasing capacity demands.
Integrated controller
We have integrated the controller functionality into each Wireless Array. We provide a host of functions, including high performance packet processing, networking, security processing, RF control, RF monitoring, and inter-Array coordination.
By placing the intelligence and packet processing at the network edge, you will gain several benefits, including:
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Linear scalability – Capacity is incrementally added to the network by simply adding Arrays, as opposed to adding entirely new, expensive controllers when their AP limit is reached
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Policy enforcement – With intelligence and processing distributed in each Array, security and performance policies can be applied with greater efficiency directly at the network edge as opposed to centrally
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Easier installation – With autonomous operation, Arrays integrate to the network infrastructure similar to a switch as opposed to a thin AP which is dependent on the connection to a central controller
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High resiliency – Each Array operates as a standalone device with no dependency or single point of failure from a central controller
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Superior network performance – By processing control and data traffic at the network edge as opposed a centralized location, application performance is enhanced and traffic latency, jitter, and roaming times are reduced and better controlled
Multi-sector antenna system
The sectored antenna design of the Wireless Array provides a superior level of RF control within the system compared to traditional wireless solutions. RF resources can be more optimally managed with this design compared to conventional Omni-directional antenna systems in areas of channel allocation, interference mitigation, and user performance.
A sectored antenna system creates slices of wireless coverage. Each slice uses a unique channel and clusters devices. This approach creates greater physical separation between sectors and devices on a given channel as opposed to Omni-directional antennas that transmit RF in all directions. Directionality of the sectors isolates radios on adjacent Arrays from interfering with each other. This together with appropriate channel design allows the reuse of the same channels by adjacent Wireless Arrays. Channel reuse is critical for a wireless network to operate at high capacity since only a limited number of channels are available, in particular with only three non-overlapping channels in the 2.4GHz band.
With our approach, you get higher RF gain. It transmits stronger signals to the wireless clients and correspondingly receives weaker signals from them since antenna gain works in both directions. Stronger signal provides better communication data rates for a client at given distance, as well as better operational range.
Application control
Identifying network traffic at the application level provides greater granularity in efficiently provisioning network resources. Critical applications need appropriate prioritization while recreational applications such as social media and gaming may need to be throttled or blocked. The ability to control traffic at the network edge before it impacts the core network surpasses the scalability of more traditional centralized solutions.
Xirrus offers application visibility and policy enforcement, called Xirrus Application Control, at the wireless edge using Layer 7 Deep Packet Inspection (DPI) technology. Unlike many other DPI implementations, Application Control goes far beyond simple port, protocol, and regex-based classification schemes to provide comprehensive and accurate application awareness.
Access management
The Xirrus Access Manager (XAM) controls network access for BYOD users and devices. Centrally managed, with customizable Captive Portal capabilities, the XAM solution offers secure and easy guest registration services and onboarding of mobile devices, whether personal or IT-issued. Different guest registration options are supported, such as hosted, self, or sponsored. Temporary accounts can be created based on length of allowed access. Devices owned by credentialed users can be easily on-boarded with 802.1x auto client configuration and dissolvable agents.
Dedicated security monitoring
Another costly network component found in conventional offerings are security monitors. Unlike the competition, we have integrated a wireless threat sensor into each Wireless Array, making it possible to have a dense design without compromising radio resources for servicing users.
Most offerings are restricted since both radios in the AP are typically required for servicing users – one operating at 2.4GHz and one at 5GHz. To perform security-monitoring functions, additional APs must be added to the network or one of the two radios must time-slice between servicing users and performing security functions. Time-slicing reduces the bandwidth available to servicing users and is significantly less efficient performing scanning functions as opposed to a dedicated radio resource.
By default, a dedicated monitoring radio in our Wireless Arrays continually scans the RF environment 24x7 covering all Wi-Fi channels in about 10 seconds. When called upon, it can perform additional functions focused on a given channel or threat as required. These functions do not interrupt the servicing of user traffic on the Array in any way.
Functions of the Array’s monitor radio include:
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Wireless threat/attack detection for wireless IDS/IPS (Intrusion Detection/Intrusion Prevention)
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Rogue AP and ad hoc station detection, classification, and mitigation
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Spectrum analysis providing performance, interference, and error information across all Wi-Fi channels
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Wireless packet capture on any Wi-Fi channel
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Proactive self-monitoring by functioning as a wireless client connecting to other radios in the Array
Dedicated wireless backhaul
The multi-radio design of the Wireless Array enables radios to be configured as a dedicated wireless backbone between Arrays. This functionality is referred to as Wireless Distribution System (WDS).
WDS eliminates the need to run wired uplinks to Arrays in areas where it may be impractical or cost-prohibitive to pull cable. All security and network policies are enforced across the backhaul links, the same as if the Arrays are connected via wired uplinks. Radio bonding allows multiple backhaul links to be aggregated, providing load balancing of traffic and fail-over capabilities for a uniform and fault-tolerant deployment.
With multiple radios available per Array, wireless backhaul can be configured on radios independent of those servicing users. Traditional enterprise APs with two radios are limited to one radio for a backhaul (mesh) connection. This radio must share the same channel as all other APs on that mesh link, severely limiting the total amount of bandwidth available for backhaul. With the Xirrus Array, backhaul connections are dedicated point-to-point links between Arrays and operate without performance compromise.
We can create up to four independent wireless backhaul links per Array and bond up to three radios together in for each link. Using 450Mbps 802.11n radios, each backhaul can offer up to 1.35Gbps of total Wi-Fi bandwidth. The connections support 802.1d Spanning tree bridging services for failover and link redundancy, including with the Array’s wired interfaces.
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. Learn more >
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. Learn more >
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. Learn more >
Cloud-based network management
Our cloud-based network management solution offers customers that have no or limited IT departments a simpler way to manage their wireless network. Our customers use the same easy-to-use interfaces as our on-premise system through an online portal. Our customers can pick from a Xirrus hosted public cloud option or host their own private cloud offering to match their needs. Learn more >