All components of the CVG are controllable via a comprehensive policy management system, which uses a number of factors to determine which policies to apply. The policy system supports the specification of conditions (which dictates when something happens) as well as the specification of filters (which determines who a policy applies to) to provide a fine-grained policy execution environment.
Conditions, which dictate when a policy event should be triggered, are typically evaluated by the CVG and include a range of possible options. These include time of day, location, network state including carrier ID/SSID, cell ID/BSSID, network standard (2G, 3G, LTE, Wi-Fi), roaming status, and APN, as well as device state including battery level, ignition state, data usage, memory/CPU usage, and running applications.
Filters, which dictate when a policy will be sent to a CVG for evaluation, include a number of more fixed factors. These include the OS the CVG is running, the current software version active, the manufacturer of the vehicle, the model of the vehicle, particular subscriber IDs (such as IMSI), the form factor (factory vs. aftermarket), in addition to customizable feature codes which can be provisioned on the CVG at install time.
All of the available features have policy-customizable behaviour. For example, the network aggregation feature uses policy to determine how to route different classes of traffic, what flows should be considered high priority from a QoS perspective, what amount of mobile data to consume, etc. The configuration of the Wi-Fi and mobile radio network parameters, including SSID, APN, and all other fields, are controlled by polices as well.
The Pravala policy management system allows administrators, owners, OEMs and Tier Ones to control the network configuration of all of the wireless radios on the CVG, including Wi-Fi and mobile. These configurations can be customized using a number of factors, allowing for very flexible deployments.
One example of a customization factor is the network operator the CVG is connected to, so that carrier-operated Wi-Fi networks will only be provisioned on vehicles with the proper SIM. As another example, data roaming could be enabled when a safety-critical update needs to be pushed to all vehicles of a particular model year, regardless of their location, to ensure that the update is distributed as quickly as possible. It would be best to combine this policy with an updated traffic routing policy to only allow update traffic when roaming, to control the update costs.
The above example demonstrates the power and flexibility of a centrally managed network policy system – it is possible to combine traffic routing and network configuration policies to quickly distribute safety-critical updates without risking large data costs if everything is able to suddenly use the mobile radio while roaming.