Wi-Fi reaches the Ethernet tipping point

Dirk Gates, co-founder and executive chairman of wireless solutions provider Xirrus, tells James Atkinson why Wi-Fi technology is ready to equal and perhaps surpass Ethernet

Wi-Fi reaches the Ethernet tipping point

Twenty years ago, Dirk Gates, co-founder and executive chairman of Wi-Fi provider Xirrus, had a vision that we would one day all be using wireless enabled technology.

He recalls that 10 years later in 2003 he attended an Intel Capital conference on Wi-Fi, which attempted to peer into the future to see what wireless technology might be worth investing in. Afterwards, Gates was even more convinced that eventually everything really would be wireless enabled one day, but he foresaw a major problem.

‘I walked out of that conference and said to myself that the infrastructure is just not going to cut it,’ he remembers. ‘The world was then, and is largely now, focused on two-radio home access points (APs). That’s fine for a few people sitting in a building, but in a business with hundreds of people you can’t tack the APs up fast enough. That’s where the concept for Xirrus came from – how to build more scalable, high capacity infrastructure for Wi-Fi.’

Wireless technology has been playing catch up for 20 years with Ethernet, according to Gates, who says: ‘The vision is that some day we will replace Ethernet at the edge, not at the data centre – maybe in another 20 years for that. The Holy Grail has been 1Gbps of speed and Ethernet has now been delivering1Gb speeds for almost a decade to the desk top.

‘I don’t see any move to go from 1Gb to 10Gb at the desk,’ he continues. ‘Wi-Fi has been slowly working its way up there from 802.11 a/g speeds of 54Mbps to 300Mbps and 430Mbps with 2x2 and 3x3 802.11n, but with 802.11ac we have finally broken through the 1Gbps target.

Ethernet tipping point
‘This is the tipping point; there really is no excuse to still pull wire now,’ says Gates. ‘2014 is going to be an exciting time for Wi-Fi, as we will see the start of this inflexion point and this 20-year vision of an all wireless technology becoming a reality.’

But it is not just about speed. Gates believes that wireless technology has also greatly improved its security and quality of service. ‘I’m going to argue that if properly deployed (i.e. not an open network) a wireless LAN is more secure than a wired LAN if you turn on authentication and encryption and every device supports it. Security has been a longstanding bogey man for wireless tech, but it is not an issue now.’

In terms of quality of service, Gates says the Wi-Fi industry has moved light years beyond where it was even five years ago thanks to the development of, and adherence to, clear standards. But there are new challenges to overcome.

‘The next frontier is going to be the issue that we at Xirrus have been trying to solve,’ he says. ‘We are moving from basic connectivity issues to: how do we tackle scalability and capacity issues in the network to meet the increased demand?’

Xirrus took a page out of the Ethernet playbook, as Gates describes it, and followed a modular approach moving from stackables to chassis-based switches when it comes to wireless, and from throwaway APs to chassis-based solutions where radios can be replaced with line cards.

‘The technology needed to pack lots of 802.11 radios into a small space and get them all to work together turns out to be non-trivial,’ notes Gates. ‘If you look around there are very few people that offer three radio APs, let alone four, eight, 12 or 16, and that’s because it is a difficult technical challenge to solve issues like radio co-ordination and interference mitigation.’

Capacity challenge
He continues: ‘The real challenge is: how do I put more radios in the air? How do I start getting fewer users per radio on what is still a shared medium? Ethernet finally got to one-to-one. It is still oversubscribed mind you, but at least the connection between me and the infrastructure is one-to-one.

‘Wi-Fi still has that challenge,’ he concedes. ‘We also still have the mentality that range is more important than capacity, but they work against each other. If I try to put in as few APs as possible, then I end up with more clients per radio and more collisions; the higher data rates go down and the quality degrades.’

The problem becomes particularly acute in the enterprises space with its high density of users. ‘In the enterprise market, we need to think about having smaller cell sizes, more channel re-use and try and get that number of users back down to that sub-10 number per AP,’ argues Gates. ‘You need more radios in the air, each covering less space and you need to do that cost effectively.’

This is where the Xirrus chassis-based or array-based design comes in. The arrays provide access points ranging from 2 to 16 radios with high-gain directional antennas. Additional radios can be added to existing chassis using the same cable runs, backhaul and back end infrastructure to provide additional capacity as demand grows.

However, Gates does warn that customers need to understand that just adding more radios at the front end will not solve all their problems. The back end infrastructure may well need to be beefed up to keep pace with the front end and capacity demand, which will only grow with the arrival of 802.11ac Wi-Fi products.

802.11ac Wi-Fi
The new 802.11ac Wi-Fi standard will bring speeds of up to 1.3Gb and most vendors are now shipping their first Wave 1 802.11ac products. So, what differentiates Xirrus’ offerings in 802.11ac?

Most vendors provide two-radio devices – one for the 2.4GHz band and one for the 5GHz band. Gates points out that there is eight times more spectrum available in 5GHz than 2.4GHz, so ideally if you are going to fully utilise your spectrum with clients that are capable of operating in 5GHz, you’d have eight times more radios operating in 5GHz than you do in 2.4GHz.

‘But every other vendor forces you to deploy them one to one,’ he says. ‘They are selling you half an 802.11ac solution, as they still have a legacy 2.4GHz radio in there that has nothing to do with 802.11ac. So, you’re either going to under deploy 5GHz and not get the benefit of clean, fresh spectrum up there, or over-deploy 2.4GHz and make it unusable.’

Xirrus’ approach is to find an architectural solution that allows you to deploy those radios in varying ratios to one another and ultimately achieve that eight times ratio. ‘What is unique about us is that all our APs are dual-band. They can operate as either as 2.4GHz or as 5GHz radios,’ says Gates. ‘You may not want an all 5GHz network when you start, but you can switch over to it when you need to.’

The company has also developed an automatic design capability in the software that will figure out what a customer’s ratio should be based on the device population and density of its Wi-Fi infrastructure. It will adjust the number of 5GHz versus 2.4GHz radios. Another unique feature is that it provides a way to restrict 802.11ac clients to only operate on 5GHz 802.11ac radios and 802.11n and other legacy Wi-Fi standards to only operate on 2.4GHz radios.

By separating the clients, and having enough radios to do that, the customer gets the maximum benefit out of its 802.11ac infrastructure and spectrum. 802.11ac clients will get better speeds and throughput than if they were sharing the radio with slower 802.11n clients.

Gates predicts that the industry mindset will shift from a focus on deploying a wireless network to deliver connectivity, to how it can be optimised so that those applications that are making money can be prioritised over those that are costing money.

Money generating offerings include applications such as location services, push advertising, or apps that allow people to get more involved in what’s going on in large public venues – electronic programmes for soccer games, online betting and ordering refreshments, for example.

‘So, for us as vendors, it is going to be about what additional value can we offer in software from a network optimisation point of view,’ says Gates.

Portfolio and market
Last year, Xirrus extended its product portfolio down to two-radio access points to provide an entry level APs to help customers get in to Wi-Fi with the confidence that they have a growth path with Xirrus, as and when they need to scale up.

‘We didn’t participate at that lower end a year ago,’ says Gates, ‘and frankly it wasn’t a big part of the market. But that lower end is growing, so we need to participate in that part of the market or we’ll get locked out.’ The hospitality sector, hotels and SMEs are all target customers in this segment of the market.

Customers operating in the SME segment of the market often do not want the hassle of having to manage a Wi-Fi network with its attendant BYOD issues – authorisations, passwords and so on. In short, they want a simpler way to manage devices.

Xirrus’s solution was to launch is cloud management service to help them. ‘It is really targeted at that end of the market, although quite a few of our current clients are interested in it too,’ says Gates. ‘They buy the products and plug them in. The product finds its cloud instance and automatically self-configures.’

Summing up, Gates says: ‘We are about to see a massive explosion in the market. Customers will go for Wi-Fi and see 802.11ac as a replacement for wired technology. The real benefits of 802.11ac comes from moving to the 5GHz unlicensed spectrum band.

‘The second major benefit is breaking the psychological barrier that says wireless is inferior to wired – this is the tipping point – 1.3Gbps from Wi-Fi versus 1Gbps from Ethernet. The next five years will see Wi-Fi kick out Ethernet,’ asserts Gates, who can see his vision of 20 years finally coming to fruition.

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