Technologies such as telephones and television have changed out of all recognition in recent years. Both are now highly internet connected, can be personalised through a mix of apps and settings, and have uses that extend far beyond original expectations. In contrast, many of the CCTV systems in use today are relatively untouched by these technological advances. Bandwidth also has a role to play in all this.
The time is right for CCTV to reinvent itself and enable business users to take advantage of the accessibility, capacity and scalability that cloud provides. However, one thing that prevents businesses from moving to cloud-based CCTV is concern about not having enough bandwidth. If their premises are in a rural area, where fixed broadband is not available, can the mobile phone network cope? If they rely on an ADSL connection, will that provide enough bandwidth? Fortunately, the idea that lower bandwidth connections cannot support cloud-based CCTV is something of an urban myth, and the answer to these questions is almost certainly ‘yes’.
Businesses should bear in mind that data security is paramount and ensure that their data is encrypted before it is transmitted to the cloud, as recommended by the ICO.
Reducing the amount of data sent
Streaming visual data to the cloud 24 hours a day is impractical for the vast majority of businesses. It is an unnecessary and expensive use of both bandwidth and storage capacity to save visual data that shows nothing useful. Additionally, the General Data Protection Regulation (GDPR) calls for data minimisation – only capturing and storing data that has a valid use.
An effective approach is to configure cameras to respond to movement triggers or to PIR sensors so that they only capture only what is interesting and useful. These features can be supported by using sophisticated individual recording schedules on each camera that are centrally set by an administrator. For example, a business may want some of its sites only monitored out of hours, while choosing to have other highly secure or more vulnerable locations monitored for movement at all times.
Another way to minimise the amount of data sent to the cloud and so reduce the bandwidth required is to set a low frame rate. As few as three frames a second are enough to ensure visual data is usable for security purposes. Compressing the data is another popular technique. It is also possible to apply analytics to identify visual data that is of interest and to trigger recording and alerting based only on that data. For example, someone moving around a room that should be empty might be of interest, but not if they are checking whether that room needs to be set up ready for a meeting or removing coffee cups afterwards. Sometimes there may be no need to send visual data at all, just metadata that suggests something interesting has been recorded.
All these measures, in appropriate combination, help businesses using ADSL, 3G or 4G connections ensure that they send only useful data to the cloud, and minimise the amount that they send.
Handling vagaries in mobile network availability
Where a fixed broadband connection to cloud storage is not an option, the mobile network is almost certainly available. While 4G coverage has increased, for many locations the best that will be available is 3G, However, there are systems available which have been designed to work effectively with 3G, particularly in combination with the techniques to reduce the amount of data transmitted already discussed.
Systems may also have to cope with ‘blips’ in mobile network availability. To handle this, Cloudview has developed a visual network adapter which constantly checks network speed. If for some reason the network is down or running slowly, it will automatically hold visual data until the network is operating at full strength again. This adapter can be added to existing cameras (digital or analogue) to provide cloud connectivity.
Estimating how much bandwidth you need
It is difficult to come up with a hard and fast rule about the minimum bandwidth a business CCTV user might need. Installations vary widely and bandwidth will depend on the number of cameras as well as the methods described for reducing the volume of data transmitted. For example, a single camera that records an hour or so of motion-triggered footage a day will need a lot less bandwidth than a single camera recording footage continuously for eight hours a day. This, in turn, will need much less bandwidth than ten busy cameras.
We have a rule of thumb based on our own experience working with businesses which says an upload speed of 200kbps to 250kbps per camera is adequate. It is worth noting that the average upload speed for ADSL hovers between 512 Kbps and 2 Mbps, for 3G it sits at around 0.4 Mbps, and for 4G is around 8 Mbps. It is easy to check your own bandwidth using any one of a number of online tools – for example, the Measurement Lab Network Diagnostic Tool.
The following estimates of bandwidth usage across three different types of site will help organisations calculate what might be appropriate for their business.
- A remote site using 4G
Assume this has four cameras capturing data at 5 frames/second, recording on average 2 hours, 4 hours, 3 hours and 1 hour respectively per day. The estimated upload bandwidth required is 1.1Mbit/sec.
- An office site using standard ADSL broadband
Assume this has ten cameras, recording a total of 30 hours per day at 3 frames/second. The estimated upload bandwidth required is 2Mbit/sec.
- A large site using fibre broadband
Assume 75 cameras recording a total of 180 hours per day at 5 frames/second. The estimated upload bandwidth required is 20Mbits/sec.
Bringing cloud-based CCTV to everyone
The ability to use 3G, 4G and ADSL fixed broadband for CCTV opens up access to commercial premises without high-speed broadband connections. This means that rural businesses, remote utility facilities and other isolated sites can replace outdated CCTV systems that require manual interventions with modern cloud-based systems. The benefits include anywhere, anytime access to visual data, alerts based on pre-set triggers, secure access to footage for authorised users, easy sharing of visual data with third parties such as security teams or the police, and strong audit trails for data protection assurance.