Why is it important to consider download speed when designing mobile websites?

Designing any website for a mobile phone is a challenging experience. As clever as the technology of the smartphone is these days, there are still certain inherent problems that the mobile website designer has to overcome if he or she is to make the website as effective as it can possibly be.  The screen size of the mobile device itself is limiting, and affects the type of content that can be incorporated into the overall design: similarly the site architecture will have to also be simplified, because moving around and navigating mobile websites is much more difficult on a mobile phone than a conventional desk top or laptop. One thing that is often overlooked is the relevance and importance of download speed. As smart as a mobile phone is, it can’t download information currently at anything like the rate of a traditional pc. It is considerably slower, and therefore this needs to be born in mind by the web designer.

How much slower are mobile phone downloading speeds?

On average, UK users achieve a mobile internet download speed of 1.5Mbps, compared with 6.2Mbps average fixed broadband download speeds according to a recent report from Ofcom. Ofcom consumer research shows that 17% of UK households are using mobile broadband to access online services, with 7% using it as their only means of internet access, compared with 3% in 2009. For those people using mobile broadband as their only internet access, 1.5Mbps bandwidth is still significantly lower that the minimum 2Mbps fixed broadband speed in the Digital Britain report. In fact, the Ofcom research found that on average, mobile broadband services perform worse than all the fixed-line broadband services measured in the same period. Average mobile broadband download speeds are around a third of the average speeds offered by “up to” 20/24Mbps DSL broadband services.

The research involved more than 4.2 million tests, measuring average speeds as well as the performance of the five mobile operators in areas of good 3G network coverage. Tests from broadband monitoring specialist, Epitiro, presented in the report show that basic web pages took on average 8.5 seconds to download. Again, this is much slower that users expect on fixed broadband. Best practice dictates that pages should load as fast as possible. Slow load times lead to user frustration and people will leave a site if it does not download quickly. In good 3G coverage areas, Ofcom found that average mobile broadband speeds were 2.1Mbps, falling to an average of 1.7Mbps during the peak evening period of 8-10pm.

Basic web pages took on average 2.2 seconds to download. Even with a connection speed of 2.1Mbps, static probe testing showed that a 5MB music track would download over mobile in about 20 seconds and a 250MB video file (for example a standard definition 30min TV programme) would download in about 17 minutes. Mobile download speeds are not likely to become any quicker until 4^th generation mobile phone technology is delivered and this could well not now be until 2013. In the meantime websites continue to run the risk of loosing dissatisfied users.

Can anything be done to overcome this problem?

TSW System Solutions believe it can. We take these statistics seriously and understand that if users are dissatisfied, then businesses may suffer financially. With that in mind we always use AJAX programming for our mobile websites. We believe this is vital and it is the only way to overcome the problems of download speeds and their effects on mobile websites. AJAX programming, or asynchronous JavaScript and XML, is a group of inter-related web development elements that can be used for our clients when we create interactive web applications. With AJAX, web applications can send data to, and receive data from, a server asynchronously: in other words in the background without affecting the display or behaviour of the existing web page. This means that pages no longer need to be reloaded each time the user sends a request. Each time a page is re-loaded all the page content disappears and then re-appears. Asynchronous loading of content prevents this.

Like DHTML and LAMP, AJAX is not one technology, but a group of technologies. AJAX uses a combination of HTML and CSS to mark up and style information. The document object model, DOM, is accessed with JavaScript to dynamically display, and to allow the user to interact with the information presented. JavaScript and the XMLHttpRequest object provide a method for exchanging data asynchronously between browser and server to avoid full page reloads.