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In the first Behind the Wi-Fi blog we looked at some of the physical aspects of building out a large scale temporary network, this time we look at how it all comes together as a ‘logical network’ or more simply how all of the networking components work together. With some event networks servicing 10,000+ simultaneous users and consuming anywhere between 100Mbps to 1Gbps of internet connectivity, chaos would ensue unless it was carefully designed and implemented.

Although networks are thought of as being one big entity in reality they are broken down into many ‘virtual networks’ which operate independently and are isolated from each other. This approach is very important from a management, security, reliability and performance point of view. For example, you would not want public users being able to access a network that is being used for payment transactions.

All of our events are rated based on a complexity score and this helps define how the network is designed. Larger and more complex events are designed using a fully routed topology rather than a simple flat design. This approach provides the best performance and resilience operating a bit like the electricity ‘grid’ network where a number of nodes are connected together in a resilient manner to provide a multipath backbone and then the customer services are connected to the nodes. This approach means that each node is provided with a level of isolation and protection which is not possible on a simpler flat network.

This isolation is important as a network grows due to the way when devices connect they are designed to send out ‘broadcasts’ to everyone on the network. With a large number of devices these broadcasts can become overwhelming on a flat network but on a routed network the broadcasts can be filtered out at the appropriate node. Faulty or incorrectly configured equipment can sometimes cause ‘network storms’ where huge amounts of network traffic is created in milliseconds reducing performance for all users, a routed topology offers much more protection against this isolating any problems to a small subsection of the network.

Every site has different network requirements so there may be anywhere between 5 and 50 virtual networks known as VLANS to ensure all the appropriate users and network traffic are kept separate. Traffic shaping rules are applied to these different networks to prioritise the most important networks, along with filtering and logging as required.

At the heart of this is what we call the ‘core’, the set of components which control the key aspects of the network such as the internet access, filtering, firewall, authentication, routing, wireless management, remote access and monitoring.

With several different connections to the internet, traffic is distributed across the different connections – this may be by load balancing, bonding, or policy routing. This is a complex area as different types of network traffic may only be suitable for certain types of connection. For example, voice traffic and encrypted VPNs do not work well over a satellite link due to the high latency (delay) of satellite.

The core routers also contain a firewall, this is the protection between the external internet and the internal network. Protecting against intrusion and hacking is sadly a very important factor with all internet connected systems subject to a constant stream of attacks from remote hackers in places such as China and Russia.

Additional firewalls also exist to control traffic across the internal networks. By default, everything is blocked between networks but for some services limited access may be required across VLANS so specific rules are added – an approach known as pin-holing. Filtering can be used to block particular websites or protocols (such as bit torrent and peer to peer networking); this may be done to protect users from undesirable content or to ensure the performance of the network is maintained.

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Prioritisation of voice traffic from phones is important to ensure call quality, especially in a media centre

Rate shaping and queuing are additional important controls to manage bandwidth to specific groups and users ensuring everyone gets the speeds they asked for. This is especially important for real-time services such as voice calls and video streaming. Traffic is managed at a user and network level using dynamic allowances so that all available bandwidth is utilised in the most effective manner without impacting any critical services. Users or networks may be given a guaranteed amount of bandwidth but this may be exceeded in a ‘burst’ mode provided there is spare capacity on the incoming internet links.

The core also houses the PBX, the onsite telephone exchange which manages all the phones and calls with big sites having as many as 200 phones and generating thousands of calls. All the features of a typical office telephone system are implemented with ring groups, voicemail, call forwarding, IVR, etc. As all of the phones are Voice Over IP (VoIP) they are connected via standard network cabling so can easily be moved between locations. Additional numbers and handsets can also be added very quickly.

The vast majority of users these days are connected via the Wi-Fi network which requires careful management and design. The detail behind this would run to several pages so for the purposes of this blog we will keep things relatively simple and look at a few key aspects.

Frequency/Standard – Wi-Fi currently operates at two frequencies, 2.4 GHz and 5 GHz. As discussed in previous blogs there are many issues around 2.4 GHz so all primary access we provide is focussed on 5 GHz with only public access and some other legacy devices connected via 2.4 GHz. All of the Wi-Fi access points we use are at least 802.11n capable with the majority now 802.11ac enabled to provide the highest speeds and capacity.

Wireless Network Names – When you look for a wireless network on a device you see a list of available networks, these identifiers are known as SSIDs and control the connection method to the network. Different SSIDs will be used for different audiences, with some SSIDs hidden such that you can only try to connect to it if you know the name. Wireless access points can broadcast multiple SSIDs at the same time but there are limits and best practice as to how many should be used. Some SSIDs may be available across the entire network whereas others may be limited to specific areas.

Encryption & Authentication – These two areas are sometimes confused but relate to two very different aspects. Encryption deals with the way the information which is sent wirelessly is scrambled to avoid any unauthorised access. It is similar to using a website starting with ‘https’ but in this case all information between the device and the wireless access point is encrypted. There are several standards for doing this and we use WPA2 which is the current leader. Not all networks are encrypted and, as is the case with most public Wi-Fi hotspots, public access is generally unencrypted.

Authentication deals with whether a user is allowed to use a particular network and ranges from ‘open access’ where a user just clicks on an accept button for the terms and conditions through classic username/password credentials and onto RADIUS or certificate based systems which offer the highest levels of protection. One common approach is the use of a pre-shared key or pass-phrase as part of the WPA standard, knowing the pass-phrase is in effect an authentication challenge. The pass-phrase is also the seed for the encryption and the longer the pass-phrase the harder it is for a hacker to crack the encryption. The pass-phrase approach is simple to manage but has inherent weakness in that it is easily compromised by sharing between users with no control.

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Large scale Wi-Fi is a particularly complex area with many different requirements and challenges

On top of this various other services are employed to protect and manage the Wi-Fi. Client isolation for example stops a user on the network from seeing any network traffic from another user, whereas band steering & load balancing seamlessly move users between frequencies and wireless access points to ensure each user gets the best experience.

The rise of the smartphone has had a major impact on Wi-Fi networks at events due to the way they behave. If a smartphone has its Wi-Fi turned on, then it constantly hunts and probes for Wi-Fi networks so even in this ‘un-associated’ state it still creates an element of load on the network. Mechanisms have to be employed to drop the devices from the network unless they are truly connected (‘associated’) and active (accessing a web page for example). Even connected devices are typically dropped fairly quickly once they cease to be active so that other users can connect. This all happens very fast and transparently to the user with the device reconnecting automatically when it needs to.

This array of logical controls processes millions of pieces of information every second routing them like letters to the correct address, discarding damaged or undesirable ones and acknowledging when they have been received. Each of the components have to work in harmony with sites having anywhere up to around 30 routers, 200 network switches and 200 Wi-Fi access points. To manage this standard configurations and builds are used which have been pre-tested as this reduces the risk of introducing a problem via a new firmware or configuration change.

Next time in the final part of this series we will look at how this all comes together to deliver the end services for the users and the impact it all has on the event.

 

photo credit: Binary code via photopin (license)

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“You guys do Wi-Fi at events right?” typically is the way most people remember us, the irony that the invisible part of our service is in reality the most visible. Unless you know what you are looking for at a large event site you are unlikely to notice the extensive array of technology quietly beating away like a heart.

From walking up to the entrance and having your ticket scanned, watching screens and digital signage, using a smartphone app or buying something on your credit card before you leave, today’s event experience is woven with technology touchpoints. Watching a live stream remotely or scrolling through social media content also rely on an infrastructure which supports attendees, the production team, artists, stewards, security, traders & exhibitors, broadcasters, sponsors and just about everyone else involved.

During a big event the humble cables and components which enable all of this may deal with over 25 billion individual electronic packets of data – all of which have to be delivered to the correct location in milliseconds.

In the first of three blogs looking behind the scenes we take a look at how the core network infrastructure is put together.

Let’s Get Physical

When an event organiser starts the build for an event, often several weeks before live, one of the first things they need is connectivity to the internet. Our team arrives at the same time as the cabins and power to deliver what we call First Day Services – a mix of internet connectivity, Wi-Fi and VoIP telephony for the production team.

Connectivity may be provided by traditional copper services such as ADSL or via satellite but more typically is now via optical fibre or a wireless point to point link as the demands on internet access capacity are ever increasing. Even 100Mbps optic fibre connections are rapidly being surpassed with a need for 1Gbps fibre circuits.

Distribution Board

PSTN, ISDN, ADSL and fibre all are commonplace on a big site

Wireless point-to-point links relay connectivity from a nearby datacentre or other point of presence, however, this introduces additional complexity with the need for tall, stable masts at each end of the link to create the ‘line of sight’ required for a point to point link. To avoid interference and improve speeds the latest generations of links now utilise frequencies as high as 24GHz and 60GHz to provide speeds over 1Gbps. Even with the reliability of fibre and modern wireless links it is still key to have a redundant link too so a second connection is used in parallel to provide a backup.

From there on the network infrastructure is built out alongside the rest of the event infrastructure working closely with the event build schedule. Planning is critical with many sites requiring a network infrastructure as complex as a large company head office, which must be delivered in a matter of days over a large area.

The backbone on many sites is an extensive optical fibre network covering several kilometres and running between the key locations to provide the gigabit and above speeds expected. On some sites a proportion of the fibre is installed permanently – buried into the ground and presented in special cabinets – but in most cases it is loose laid, soft dug, flown, ducted, and ramped around the site. Pulling armoured or CST (corrugated steel tube) fibre over hundreds of metres at a time through bushes, trees, ditches and over structures is no easy task!

Optical fibre cable can run over much longer lengths than copper cable whilst maintaining high speeds, however, it is harder to work with requiring, for example, an exotically named ‘fusion splicer’ to join fibre cores together. On one current event which uses a mix of 8, 16 and 24 core fibre there are over 1,200 terminations and splices on the 5.5km of fibre. With the network now a critical element redundancy is important so the fibre is deployed in ‘rings’ so that all locations are serviced from two independent pieces of fibre – a tactic known as ‘diverse routing’ – so that if one piece of fibre becomes damaged the network continues to operate at full speed.

Each secure fibre break-out point, known as a Point of Presence (POP), is furnished with routing and switching hardware within a special weatherproof and temperature controlled cabinet to connect up the copper cabling which is used to provide the services at the end point such as VoIP phones, Wi-Fi Access points, PDQs and CCTV cameras.

Each cabinet is fed power from the nearest generator on a 16-amp feed and contains a UPS (Uninterruptible Power Supply) to clean up any power spikes and ensure that if the power fails not only does everything keep running on battery but also an alert is generated so that the power can be restored before the battery runs out.

Although wireless technology is used on sites there is still a lot of traditional copper cabling using CAT5 as this means power can be delivered along the same cable to the end device. Another aspect is speed, with most wireless devices limited to around 450Mbps and shared between multiple users the actual speed is too low for demanding services, whereas CAT5 will happily run at 1Gbps to each user.

For critical reliability wireless also has risks from interference so where possible it is kept to non-critical services but there are always times when it is the only option so dedicated ‘Point-to-Point’ links are used – these are similar to normal Wi-Fi but use special antennas and protocols to improve performance and reliability.

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A head for heights is important for some installs!

Another significant technology on site is VDSL (Very High Bit-Rate DSL), similar in nature to ADSL used at home but run in a closed environment and at much higher speeds. It is the same technology as is used for the BT Infinity service enabling high speed connections over a copper cable up to around 800m in length (as opposed to 100m for Ethernet).

All of these approaches are used to build out the network to each location which requires a network service be it a payment terminal (PDQ) on a stand to a CCTV camera perched high up on a stage. Although there is a detailed site plan, event sites are always subject to changes so our teams have to think on their feet as the site evolves during the build period. Running cables to the top of structures and marquees can be particularly difficult requiring the use of cherry pickers to get the required height.

After the event all of the fibre is coiled back up and sent back to our warehouse for re-use and storage. The copper cable is also gathered up but is not suitable for re-use so instead it is all recycled.

The deployment of the core network is a heavy lift in terms of physical effort but the next step is just as demanding – the logical network is how everything is configured to work together using many ‘virtual networks’ and routing protocols. In part 2 we will take a look at the logical network and the magic behind it.

 

Photo Credit: Fibre Optic via photopin (license)

Event technology plays a major role in the way we plan and organize our events today. According to the below infographic, which takes a close look at the impact of technology on the success of events in 2016, a huge 75% of event professionals are expected to buy apps to facilitate engagement with their audience. Many companies have also stepped up their live streaming activities to reach a larger audience and stand out from the competition. Social media, which offers companies powerful opportunities to promote event awareness or create a new information channel, remains another top favourite.

Of course all of this introduces potential complexity which requires detailed knowledge and planning across a broad spectrum of technology. With the summer season of events already ramping up fast it is critical that organisers plan well in advance and work with the right experienced people to ensure all the different aspects are integrated into a realistic and workable solution. Last minute panics on-site are not desirable and generally push up costs, a well planned, integrated approach is much better!

Source: http://www.losberger.co.uk/

Event Technology: Will This Define Success in 2016?

15360051168_4162e2067e_kSorry to disappoint, but yes our blog last week on Li-Fi at festivals was an April Fool’s joke. The response to it though highlights just how much importance people put on remaining connected whilst at events.

Li-Fi is a real technology and does hold promise but it is practically much more suited to indoor environments and certainly not outdoor lighthouses! As with many technologies theoretical speeds are indeed very fast in the lab but real-world use is some way off, in the meantime Wi-Fi and 3G/4G remain the primary options for keeping connected.

All is not lost though as these technologies continue to develop, and more and more events are deploying infrastructure to improve attendee experience. Wi-Fi has moved a long way from the days of 11Mbps 802.11b, one of the first standards. Modern 802.11ac wireless access points support far more users, offer much higher speeds and contain a raft of technology to create the best user experience. A well designed high-density Wi-Fi deployment using 802.11ac and directional antennas can support thousands of simultaneous users and still provide good speeds.

The rapid deployment of 4G infrastructure by mobile carriers has improved connectivity at smaller events but events attracting more than a few thousand quickly overload cell towers which are limited by spectrum availability and coverage size.

Testing is underway with new technologies which may help – the first is LTE-U (Long Term Evolution Unlicensed) which more simply put is using unlicensed spectrum such as 5 GHz to deliver additional 4G capacity. The challenge is that this technology introduces yet another connectivity method into what is becoming very congested spectrum. It is in effect robbing Peter to pay Paul and therefore the approach has split the industry due to concerns over the impact it may have on Wi-Fi installations.

Another approach in testing, supported by Ruckus and Qualcomm amongst others, is OpenG using shared spectrum at 3.5 GHz in the US. It is not dissimilar to LTE-U but because it uses different shared spectrum does not clash with existing Wi-Fi. With the Ruckus solution the 3.5GHz radio is being integrated into existing dual-band Wi-Fi access points providing a triple radio solution in one unit which can be deployed easily.

Wi-Fi also continues to evolve with 802.11ac now at ‘wave 2’, a fuller implementation of the standard featuring ‘Multi-User MIMO’, a way of better utilising spatial channels across devices giving increased capacity. Then there is 802.11ax, touting speeds of 10 Gbps but we won’t see that any time soon as the standard is unlikely to be ratified until at least 2019 by which time Li-Fi may also be a reality!

Unfortunately, as is typical with these mobile technology evolutions, once testing and approval is complete there is a lag whilst the mobile handset manufacturers catch up with integrating the technology and penetrating the market which can add several years before mass market adoption is reached.

In the meantime, well implemented 802.11ac Wi-Fi remains the best approach for high density connectivity, and that’s certainly what we will be using this summer.

Lighthouse

During the summer of 2016 Etherlive will be piloting the innovative new Li-Fi (Light Fidelity) technology at a range of festivals and outdoor events. Operating in a similar way to Wi-Fi the technology uses light rather than wireless signals to transmit data to mobile devices and can offer very high data rates up to 1,000 times faster than Wi-Fi.

To enable this existing mast structures used on sites for CCTV and wireless transmission will be converted to ‘lighthouses’ firing out powerful rapid oscillating infrared beams. Early adopters will be offered an adapter for their mobile devices which when worn externally (such as on the head) will receive and transmit a light pattern to the lighthouse. The device can operate with both infrared and visible light so that at night the festival can be illuminated with thousands of tiny LED lights in multiple colours depending on the speed of connection (green for high speed, amber for slow, red for not connected).

To overcome the issue of more crowded areas the external antennas will be extendable to provide extra height, and will conveniently double up as a lantern when used inside tents.

Etherlive are working in conjunction with Li-Fi developers on this new exciting technology to be known as the Advanced Photocell Rotating Illuminated Lighthouse Gen 1 which can be used alongside our existing range of technology services.

Watch out for which events will be supporting this new initiative over the coming months!

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Easter always marks a transition point for us – from delivering service primarily to indoor events to the large scale outdoor events. With Easter chocolate consumed there is a rapid ramp in activity both internally and from our customers as plans are finalised and delivery commences in what becomes a back-to-back run until October.

Every year there is talk of ‘the next big thing’ and exciting technologies on the horizon but in reality at the sharp end of delivery the evolution, rather than revolution, of key services is just as important. So with the summer ramp about to start here are four key event technology areas to focus on.

Connectivity

It all starts with connectivity and if one thing is certain it’s that events need more capacity each year. From the data we have gathered over the last eight years you could probably build a complex theorem about the increase rate but in general we see a need for at least a 25-35% increase year on year, and often more depending on what additional services are required. Lack of internet capacity on site remains one of the most common and frustrating issues at events and this is normally down to a lack of budget or not spotting potential issues like high usage due to a mobile app or streaming.

There are trigger points at which existing services such as ADSL, FTTC (the next generation of ADSL), satellite and certain fibre services become limiting and need to be replaced with higher capacity solutions and many of those services can have significant lead times so it is important to plan connectivity as soon as possible.

Payment Systems

The debate around traditional ‘chip & PIN’, closed loop payment systems (wristbands) and open loop systems (‘contactless’) may be ongoing but it doesn’t really matter which route you choose; attendees, exhibitors and traders simply want payment systems that work.

Early, clear communication on what solutions are available at an event is critical as traders and exhibitors need support through this somewhat complex & confusing area. Expecting mobile GPRS payment terminals to work reliably on a crowded event site is crazy and can have a significant impact on revenue.

System Integration

Each year the integration between different aspects of technology at events becomes more complex and the need to coordinate and manage all the different requirements becomes more important. From the basics of wireless spectrum management & access control, to the adhoc needs of sponsors, audio & broadcasters, each requirement can have an impact on the success of an event so the sooner it is identified the better it can be dealt with.

Safety & Security

The area of safety and security breaks into two areas – the use of technology to help manage and secure the event, and the security of the technology itself.

Sadly, hacking isn’t just something that happens to governments and large companies, it is a continuous real threat. Externally we see frequent attempts to access services and systems from locations such as Russia and China. This is going on all the time across the internet and event sites are just as prone to access attempts as any other internet node.

Risks also exist within an event site, generally from people just trying to access Wi-Fi networks but sometimes the intent is more sinister. With so many critical services running on event networks maintaining appropriate security is essential. Encrypted, managed networks, strong authentication, intrusion detection, client isolation and firewalls are just some of the techniques required to keep the network secure.

Using technology to keep an event site physically safe and secure has become increasingly important over the last few years. The obvious aspect is CCTV with high definition cameras capable of excellent detail and response but there is much more available to organisers. Visibility of real-time access control data from gates, scans of social media streams, Automatic Number Plate Recognition (ANPR) of vehicles entering a site and ‘heat mapping’ of devices across an event site can all be combined to provide an insight to event control of what is happening on site.

Event technology has already come a long way from just being about internet access and it continues to evolve rapidly but this evolution and dependence requires an increased focus on planning to ensure it all comes together seamlessly.

Event Technology Myths

For our third myth busters article Wi-Fi becomes the focus, touching on the relationship between microwave ovens, water and Wi-Fi, wireless signal propagation and Wi-Fi security.

My microwave oven stops my Wi-Fi from working properly – TRUE (but not always)

For the non-technical the idea that whilst warming up a bowl of soup in the microwave oven you struggle to browse the internet on your Wi-Fi seems bizarre but it can indeed be true. The reason is quite straightforward – the frequency of the microwaves used in a microwave oven are around 2.4GHz which is the same frequency as used by one of the two Wi-Fi bands. The issue can occur because microwave ovens are not always perfectly shielded so some of the microwaves can leak out (harmlessly) and interfere with the Wi-Fi. Industrial microwaves tend to be more of an issue as they use higher power.

The good news is that the 5GHz Wi-Fi band which is now more commonly supported in devices is not impacted by microwave ovens – although it can be affected by RADAR but that’s another story!

My Wi-Fi works through walls but not through trees – TRUE

The way wireless signals propagate through objects is quite a complex area but there some general rules. The first relates to 2.4GHz Wi-Fi and interestingly links back to microwave ovens. The reason microwave ovens operate around 2.4GHz is that this is the resonant frequency of water so if you bombard water with 2.4GHz microwaves the molecules vibrate vigorously and the water (or your food that contains water) heats up. This is great when you want to cook bacon quickly but no so good when you want to pass a 2.4GHz Wi-Fi signal through trees which contain lots of water – the signal is simply absorbed into all the water.

It is very important to note that Wi-Fi signals are extremely low power in comparison to a microwave oven so you will not cook yourself if you absorb Wi-Fi signals! On event sites trees can become a real bane for the IT engineers trying to run wireless links which is why you will hear them talking about ‘Line of Sight’.

When it comes to walls it does depend on the type of wall – a basic plasterboard or normal brick wall will only absorb some of the Wi-Fi signal, a more substantial wall will absorb more. Walls which have metal mesh in them will often block Wi-Fi altogether. On the whole though a strong Wi-Fi signal will pass through most normal walls. Windows can help or hinder depending on the type of glass used as modern thermal insulating glass can block Wi-Fi signals quite effectively.

Temporary structures at events sites are a whole case in themselves, some temporary cabins are near enough transparent to Wi-Fi but others, particularly the newer well insulated variety, are just about impervious requiring Wi-Fi access points in each cabin. Marquees and other temporary structures often exhibit a different behaviour, being transparent in good weather but more opaque when it starts raining! The water coats the marquee or structure and can create a reflective layer and also absorb signals so that less signal gets through.

The second element of this relates to the frequency of the Wi-Fi as when it comes to wireless signals the lower the frequency the greater the propagation. This is seen most obviously when you have dual band Wi-Fi operating at 2.4GHz and 5GHz. The lower frequency 2.4GHz signal will travel further than the 5GHz signal, and this becomes an important point when designing Wi-Fi coverage (along with lots of other factors!)

All Wi-Fi networks are insecure – BUSTED

Because Wi-Fi is a broadcast technology that passes through the open air anyone with the right equipment can pick up the signal, for this reason it is very important that these signals are encrypted to avoid information being intercepted by the wrong people. One of the most common ways of encrypting a Wi-Fi network is by using a technology called WPA2 – Wi-Fi Protected Access.

WPA2 is commonly set-up with a Pre-Shared Key (PSK), this alphanumeric string should only be known by those who need access to the network and they enter the key when they are connecting to the network. The potential problem with this approach is that the PSK is used to generate the encryption key and if you use a weak key then the network is left open to a fairly simple attack which can gain access to the network within minutes.

The solution is simple – longer and more complex keys! For every character added the cracking process becomes considerably harder by a factor of compute years. The question is how long. There is no agreed answer on this as it depends on how random the key is. A truly random key of 10 alphanumeric characters is actually very hard to break, taking many years but a similar length key using dictionary words could be broken very quickly.

To be safe we normally recommend a minimum of 12 characters with typical password rules – upper and lower case, numeric characters, special characters and no dictionary words unless they have character replacements.

Of course a strong key only remains strong whilst it is only known by those who should know it and this is a weakness of the shared key approach as if the key is leaked, security across the network is compromised. There are additional factors that can be introduced to improve security further – for example one technique is called Dynamic Pre-Shared Key (D-PSK) which uses dynamic, unique keys for each user so there is no risk of a leaked key.

We will cover Wi-Fi and general network security in more depth in a later blog but with the right set-up Wi-Fi networks are perfectly secure – more so than most wired networks!

Event Technology Myths

In the second part of our myth busting we look at satellite, high density Wi-Fi and broadband speed.

Satellite is the best all round solution for quick event deployment – BUSTED

Over the last few years KA band satellite has become a cheap option for temporary internet access, it can be a great solution in certain cases but there are many cases where it is not suitable. Satellite suffers from a high latency due to the distance to the satellite and this means every piece of data takes around 600ms to cross space. That delay might not seem much but it is crippling to services such as VPN (Virtual Private Networks), VoIP, video calls, online gaming and any application which requires lots of rapid two-way data traffic. It is great however for large file uploads and video streaming, however, it is important to watch data usage as this can rack up significant additional costs.

Satellite is also a poor solution for wide-scale access such as public Wi-Fi, this is because of a technology it uses to try and boost speed, the downside of which limits the number of simultaneous users who can connect to one satellite service. Most KA satellite services also have high contention ratios which can reduce the advertised 18Mbps/6Mbps type speeds down to something considerably lower, a similar trick is used with home broadband services. Uncontended services are available but the cost is much higher and other than for short durations (it’s normally sold in 15 minute slots) it is not competitive with other solutions.

Satellite can absolutely be the right approach, and we deploy lots of satellite solutions, but understanding the user requirements and explaining what the user experience will be like are extremely important to avoid disappointment and frustration.

Better Wi-Fi just means using more Wi-Fi access points – BUSTED

One of the most common problems with Wi-Fi networks is too many Wi-Fi access points and a poor design. A typical response to a user complaining about Wi-Fi is for another Wi-Fi access point to be deployed to ‘improve coverage’, yet frequently this just makes matters worse. Large scale and high density Wi-Fi requires very careful design to avoid what is known as Co-Channel Interference (CCI) where multiple wireless access points are in effect shouting at each other and slowing the whole network down.

Using fewer high capacity managed wireless access points with a detailed radio spectrum design, often with focused antennas, can deliver much high capacity and a better user experience than a thick blanket of access points. Good Wi-Fi design is a technical art requiring some very detailed knowledge – the output though is pretty much invisible to the normal user until it doesn’t work!

20Mbps of broadband speed is always the same – BUSTED

It would be nice if the experience and speed of all broadband services were the same so that when you are told you have 20Mbps that’s what you get. Reality is somewhat different and more complex due to a number of factors:

  • Contention Ratio – Nearly all providers contend their services, which effectively shares the capacity between multiple users, this can be as much as 50:1 whereby your 20Mbps is shared between 50 users! More normally 20:1 is seen, then 5:1 on more business (and expensive) orientated services, up to the perfect 1:1 (no contention).
  • Asynchronous / Synchronous – ADSL and FTTC (known as BT Infinity but also sold under different names) services are asynchronous, this means that the download speed is not the same as the upload speed. The original principle was that people need more download than upload speed but with modern cloud services, video calls and general rich media this has changed considerably and a low upload speed can be more crippling than the download speed. For example, you may have an ‘20Mbps ADSL service’ but typically the upload is only 768kbps and if the upload is at capacity the download becomes throttled due to the way TCP/IP networks work. Services such as true optic fibre (also sometimes called leased lines) are synchronous.
  • Connection Speed / Throughput Speed – This is primarily an issue for ADSL/FTTC but can be seen with other services too. The speed advertised by an ADSL modem when it connects is only the theoretical speed of the link between the modem and the local exchange. The real throughput or speed depends on the entire route from your computer to the location you are connecting to – this is a complex web of routers, fibre and ‘internet peering’. Different parts of that route may suffer congestion and reduce the overall speed of the connection. Choice of Internet Service Provider (ISP) is an important factor as the good ones have better peering and higher capacity links to reduce the risk of congestion and optimise routing.
  • Latency – Every device, cable and piece of fibre on a network through which data has to pass introduces an element of latency or delay- that’s due to physics. The amount of delay depends on distance (hence why satellite is a problem), quality of links (a poor link needs to use more error correction which adds delay), utilisation of links (high utilisation adds delay) and the number of routers, switches, etc. in the path. Good services may only add a few milliseconds of latency, poor ones several hundred milliseconds and that can make a big difference to user experience.

That’s it for issue 2. Next time, does my microwave really break my Wi-Fi? How comes Wi-Fi works through walls but not though trees? And should you worry about network security.