What is intelligent caching?

13 May 2011 |


Intelligent caching is used as part of media optimisation programmes to enhance the user experience of internet video content on wireless networks.

According to Cisco Visual Networking Index (VNI), the amount of internet traffic will grow five times over between 2009 and 2013, and video content will account for 90% of this huge increase. Telcos need to adapt to this growing demand and be able to provide consistent videos without the end user experiencing buffering or stuttering content. They can do this by increasing capacity but also through intelligent caching, by embedding media optimisation mechanisms into the network that can identify and fix any potential problems with the content.

How is intelligent caching different from other forms of caching?

Intelligent caching means analysing the data traffic for patterns and seeing if there are particular videos that are likely to be downloaded multiple times in a short period. It then takes the content from the internet in its original quality and compresses it into different size levels before storing it in a local cache. The main characteristic that differentiates intelligent caching is that content is optimised on multiple levels in order to respond with the right content based on network characteristics and will only respond with the cached (and optimised) version when there is congestion in the network.

Content optimisation started with 2G networks, compressing all content flowing through the network to ensure a satisfactory user experience. Ram Venketaramani, director of product management and marketing from Openwave says: “From an optimisation standpoint the key driver for 2G networks was optimisation through brute force. But with the generation of HSPA+ and 4G networks the need is more for a congestion aware optimisation. In essence the optimiser should step in with optimised content only if the user experiences congestion problems like video stalls. Otherwise it should simply stay out of the data path.” Developers now recognise that with the introduction of 3G and 4G networks, optimised cache delivery is only necessary when there is limited bandwidth. Intelligent caching acts as an insurance policy for the networks to ensure quality video content.

What benefits does intelligent caching bring to operators?

Mobile networks, by design, have more dynamic network conditions and do not have the guarantee of a fixed network. A system built into the network that can attune the video bit rate to the network conditions being experienced means that operators can have greater assurance of the quality that their customers are experiencing.

Software companies such as Openwave Systems provide mechanisms to sit in the mobile networks and watch the flow of traffic. Venketaramani explains that, besides the user-experience benefits of delivering compressed data, the ability to pre-optimise the content reduces the cost of transcoding video content; video content is approximately five to 10 times more expensive to transcode from a CPU cost standpoint. Another benefit is the almost instantaneous speed at which networks can deliver content. Pre-processing content means that delivery to the end-user can happen more quickly.

Overall intelligent caching is designed to enhance the customer experience to watch uninterrupted video via their mobile network.

How does intelligent caching work regarding net neutrality?

Intelligent caching is connected to issues and debates of net neutrality because of the software’s ability to dynamically optimise video traffic flows. Issues occur if a company is seen to be optimising any content provider’s content without explicit permission from the content provider. Carriers must also show that they do not differentiate between content providers and treat all traffic flows equally. Intelligent caching achieves this capability by delivering the optimised version only if the end device is experiencing network issues.

How will this technology develop in the future?

Today intelligent caching takes place in the services layer (data centre) of the carrier network. Companies like Openwave are looking at ways to move to the mobile network edge to realise more savings.Venketaramani says: “We’re looking into ways to get our technology into the network edge by partnering with relevant network equipment vendors so that we can realise increased savings to our carrier customers.”