Event Tech Knowledgebase
Our guide for event organisers and production managers to simplify terminology, detail the pros and cons of different services and provide some example setups for different types of events. Click on the headings for a list of questions and answers or use the search box below.
Internet connections have to send information in two directions – sending requests from clients up the internet and then downloading the response. Many internet connections such as ADSL and satellite are asynchronous, which means their upload and download speeds are different. For example a standard ADSL connection may have a download speed of 18Mbps but the upload speed will only be around 0.75Mbps. For events in most cases it is important to have synchronous connections, where the upload and download speeds are the same, because these days there is just as much requirement for uploading as there is for downloading. Often if an asynchronous connection is used the upload speed will rapidly become a bottleneck impacting performance for everyone.
The speed of internet connections is specified in ‘megabits’ or Mbps so you often hear people saying things like ‘it is a 20Mbps connection’. The headline speed is only one factor in the actual user experience and another big factor is the ‘contention ratio’. In simple terms this refers to how much the internet connection is shared with other customers. A typical domestic broadband connection for example often has a contention ratio of around 50:1 meaning there can be up to 50 other users trying to share the bandwidth. Business connections are often 10:1 and a true dedicated link such as a 100Mbps fibre is 1:1 or uncontended. For events it is important to have a low contention ratio otherwise the actual speed of connection available may be much less than expected.
It’s all too easy for one user to hog lots of bandwidth by streaming videos and downloading huge files so rate limiting is a technique used to ‘throttle’ an individual user (or sometimes groups of users) to ensure they can only use a certain amount of bandwidth. In it’s more advanced form the user may only be restricted if the connection is at capacity, allowing the user more capacity when the network is less utilised. By doing this the overall experience for all users is maintained.
At some sites it is not possible to have one large internet connection so instead several connections may be aggregated. There are two main approaches to aggregation – load balancing and bonding. Load balancing, as the name suggests, is an approach where traffic is split over the different connections using a set of rules – the key aspect of load balancing is that an individual user can never get a faster speed than the maximum speed of one of the individual connections. Bonding operates by combining all the connections into one virtual connection which means an individual user can experience a maximum speed which is the roughly the sum of the individual connections. However, there are downsides to bonding, for example there is an overhead to the bonding process which reduces the overall speed and typically the bonding process has to work based on the performance of the slowest connection which often means a bonded connection is quite inefficient.
Whenever you use the internet digital packets of data are being sent to and received from the website or service that you are using. Generally this happens incredibly quickly, just a few milliseconds to complete a round trip so you are unlikely to pay much attention to how long it takes, however, the Round Trip Time or Latency can be more significant on certain types of internet connections. A poor ADSL connection, for example, may be over 100ms but a satellite connection will always be over 600ms. This may not sound that significant but it is when you consider how many packets of data are going backwards and forwards. The effect of this latency is particularly significant for voice conversations and encrypted traffic such as VPNs.
ADSL is well known as a main technology for home broadband because it runs over regular telephone lines and is widely available. One of the downsides of ADSL is that it is asymmetric, meaning the download speed is much faster than the upload speed. Some offerings are also highly contended leading to erratic performance. It is still widely used on event sites because of its availability and short lead times for installation but it is being replaced by FTTC (Fibre to the Cabinet) and high-speed optic fibre services. As ADSL requires a copper wire connection it can only be activated once a traditional phone line is installed.
Satellite connectivity creates more questions and churn than any other form of connectivity, primarily because it is often mis-sold. A modern KA-based system is quick to deploy, relatively cheap and has enticing headline speeds of up to 20Mbps download and 6Mbps upload. However, there are some significant limitations, firstly the receiving dish requires ‘line of sight’ to the southern horizon which often means it needs some height to see over buildings trees.
Secondly, the standard consumer and business packages are contended meaning the available bandwidth is shared with other satellite users – this may be as high as 50:1 leading to erratic and poor performance. There are alternative services such as ‘Newspotter’ which have lower or no contention but the cost of these is significantly higher. The cost of data on satellite can also be quite expensive, especially outside of the standard packages.
The big problem with satellite is latency – the time it takes for packets of data to traverse up and down to the satellite, this will always be around 600ms and causes issues for any ‘real-time’ type applications such as online gaming, voice (VoIP), two way video (video streaming is fine) and most VPN services. Even normal web browsing is a very different experience on satellite compared to other methods of connectivity.
All things considered though satellite has its place and is widely used, for some needs such as video streaming or very quick deployments where no other service is available, it is ideal. The key point is setting expectations correctly.
With the advent of 4G the use of mobile broadband has increased significantly and in some areas the speed of the connection is good enough to support a number of users. For professional use high gain antennas can be used to improve the signal and often multiple 4G connections are aggregated to provide more capacity and improve reliability, especially when the connections are aggregated from different mobile operators.
Data costs can be significant so 3G/4G is not ideal for high volume, but most importantly 3G/4G cannot be relied on for critical services. Although there are ways to improve the service there is always the risk that the connectivity will become overloaded from other users in the area, this is particularly significant for events where the service may run fine until attendees arrive and then the performance falls off.
In towns and cities the service is quick to deploy and great for general ono-critical use, in more rural areas capacity can be an issue even if there is a relatively good signal strength.
With the increased availability and reducing price of optic fibre, EFM (Ethernet First Mile) is less common than it was a few years ago. EFM runs over traditional copper cables but in effect bonds a number of lines together to provide a synchronous, uncontended service, typically up to around 30Mbps. It requires special equipment in the telephone exchange and at the client end so is only available in certain exchanges – mainly large cities. Cost wise it is cheaper than optic fibre, however, for short term needs a WISP/Wireless Point-to-Point Link may be a more cost-effective option.
Getting high capacity internet connectivity to locations at short notice can be very tricky as generally there is a long lead time on any wired or fibre circuits. Using a wireless point-to-point link from a WISP (Wireless Internet Service Provider) can be a great solution if the conditions allow. As the name suggests these links are created using a special type of wireless adapter, typically from the roof of a building or a mast. In general these links require ‘line of sight’ between the two points and work at one of several frequencies to minimise interference. Depending on the location and distance speeds similar to optic fibre can be achieved.
Wireless point-to-point links are relatively expensive and do require some planning and assessment so are not suitable in all cases. There is also still a risk of interference causing problems even though special frequencies are used, however, for critical events this risk can be minimised by using two links from different locations running at different frequencies.
FTTC is more often known by the consumer marketing names such as BT Infinity. It is a stepping stone to true fibre (FTTP – Fibre to the Premises) as the last part of the service is still delivered over the existing copper wires, meaning that the headline speeds are only available within close proximity to an enabled cabinet – normally around 800m. The benefit over ADSL is that the upload speed is considerably better – anything up to around 19Mbps depending on various factors. Download speed is also generally much faster, typically with limits of around 50Mbps. The services are contended at different levels depending on the service purchased with business services offering a lower contention ratio.
The primary downside of FTTC is availability with many areas either not having it at all, or suffering limited roll-out. Often initial surveys will say that FTTC is available but at the time of install it is discovered that the particular cabinet which connects to the install location is not enabled for FTTC. Because FTTC is delivered over copper wires a traditional phone line has to be installed prior to the FTTC service being installed.
True optic fibre connections are the place where all events would ideally be – high speed, low contention, reliable and very low latency. Only a few years ago having a 100Mbps fibre connection on site was a luxury, now many sites are moving to 1Gbps fibre connections as demand continues to increase. Cost has fallen significantly over the last few years but it is still a significant investment which tends to only work where events will be using the same location for at least 3 years.
The primary problem with fibre is the lead-time to install – typically at least 3 months and often longer, coupled with what are known as ‘ECCs’ or Excess Construction Charges. Because a fibre connection requires an optic fibre cable all the way to the final location it often requires some significant physical installation – a new fibre being ‘blown’ through a duct or an actual physical duct being installed requiring ground works. Depending on the distance to the nearest location which has a fibre point these ECCs can run from just a few hundred pounds to over £100k! Any new fibre installation is subject to a survey after which any ECCs are detailed and the order can be cancelled.
There are many good aspects fo fibre though from normally a 1:1 contention ratio through to the ability to ‘burst’ capacity. Bursting means that a connection can be kept running at a much lower speed for most of the year with a ‘burst’ to a higher speed only when there is a requirement. This approach can keep the cost down significantly.