Cloud is not a silver bullet: A Case Study of Cloud-based Mobile Browsing

Motivation:

A cloud-based browser combines an application on the device with powerful cloud servers to make the browsing experience faster, simpler and more data-efficient. The cloud does much of the work of rendering and optimizing the web page and as a result reduces the amount of data transmitted to your device and the processing power needed on the device. This is the general claim of the cloud based browsers but the author shows in his case study that though the cloud browser is a popular browser it is not significantly better than a device based browser.

Main Points:

• The evaluation of the case study is primarily focused on two metrics
  (a) Page download time
  (b) Device energy consumption.
• The Cloud Browser uses a Cloud Browser Markup Language (CBML) .The CBML employs data compaction techniques on the web page re-sizing images and compression of data.
• Page download time is the time from the first SYN and the last ACK for all objects in a page. This information can be obtained by tracing packets on a device.
• The total energy metric consists of two components the CPU energy consumed by a browser to download a web page and render it and the network energy consumed by the radio interface for a web page download.
• Pages that are heavy on Java Script(JS) code run more efficiently on Cloud browser with respect to Direct browser in terms of energy consumption.
• When the user interactivity is high offloading the JS may not be the best decision as it will consume more energy.
• Data compaction will not be always beneficial in the Cloud Browser as sometimes the energy required to compress the data will be more than downloading the actual JS.

Trade offs:

• The paper is evaluated mainly on just two areas viz 'Page download time' and 'Device energy consumption'.There are other areas which could have been considered like start time,privacy,security etc.
• The results are based on download of the first single web-page which may not give the best results.
• The paper mentions that all the experiments are done in a single location. The results may wary if the experiments are performed on several other geographic locations.
• The paper focuses on proving that direct browser is better than cloud browser but in many of the results the cloud browser performs significantly better than the direct browser.