Purpose

The purpose of this policy is to secure that devices in Tele2’s and Tele2’s partner networks communicates in a way that does not jeopardize the quality of the network, is conservative of resources, that technical solutions are of high quality, maintainable and cost efficient and to ensure that Tele2 can deliver with high quality of service towards customers and partners.

Additionally, this policy outlines recommendations regarding IoT customer device capabilities, emphasizing the importance of customers acknowledging the risks and responsibilities associated with their solution. This is particularly crucial in Telecare, a subsection within IoT healthcare that primarily deals with life-critical applications and business operations. Ensuring that devices meet stringent standards is essential to maintain the integrity and reliability of services provided in this sensitive and vital area.

Principal

• Contract refers to policy which defines the requirements
• Customer confirms compliance
• Tele2 validates compliance
• Device operates at all times according to policy

Network Communication Policy

Tele2 has divided the policy into 6 areas

A: Peak Signalling Management

• Includes that network activities may never be synchronized and devices’ back-off behaviors during communication failures.

B: Conservative Use of Resources

• Limit the amount of resources that the device consumes by measurements such as using standard errors in the modems to take correct actions when communication fails and when GPRS sessions shall be torn down or not.

C: Standard Compliance

• Devices must be compliant with GSM/UMTS standards

D: Maintainable Solution

• Remote device management, SIM-OTA, firmware upgrades

E: Critical Solution Risk Awareness

• Importance of a redundant connectivity solution

F: Quality Assurance

• Test and release management

Peak Signalling Management

Network activities shall NOT be synchronized.

Why: Synchronizing the activities, i.e. when a large number of devices connects to the network or sends data at the exact same time might have a negative effect on the network. The activities shall be evenly spread over a period of time by for example randomizing when each device connects to the network

Modem shall NOT be configured in Auto-Retry mode and an acceptable retry mode shall be implemented.

Why: Failure to comply with manage retry might cause the devices to have an aggressive behavior causing excessive signalling with the network that might have a negative effect on the network.

When an application get a clear and actionable error code, the application logic shall take appropriate action. When the application does not get a clear and actionable error code the following retry policies are acceptable:

GSM/GPRS registration failures:

• Reboot every 5 minutes, no more than 4 times. Additional reboot is acceptable after 30, 60 and then every 60 minutes, i.e. reboot at minute 0, 5, 10, 15, 20, 30, 60, 120…

SMS failures:

• Retry every 30 second, no more than 4 times. Additional retry after 15, 30, 60 and then every 60 minutes, i.e. retry at second 0, 30, 60, 90, 120, and minute 15, 30, 60, 120…

PDP Context Activation failures:

• Retry every minute, no more than 4 times. Additional retry after 15, 30, 60 and then every 60 minutes, i.e. retry at minute 1, 2, 3, 4, 5, 15, 30, 60, 120…

No traffic/Server down

• Resets every minute, no more than 4 times. Additional reset after 15, 30, 60 and then every 60 minutes, i.e. retry at minute 1, 2, 3, 4, 5, 15, 30, 60, 120…

Conservative Use of Resources

Modem error reporting shall be used to control device back-off behavior.

• Why: By having the device to react on the modem error reporting instead of a general policy retries can be avoided, thus reducing unnecessary signalling.

Customer shall make sure that devices are switched off when subscription is terminated.

• Why: The device might keep signalling even all traffic is rejected and the SIM card is cleared causing unnecessary network traffic.

PDP context should be torn down if no new data session is expected.

• Why: Keeping the data session alive when no traffic is expected keeps unnecessary resources in the network occupied. This does not apply for LTE-M devices using PSM.

Any keep-alive functionality, such as running traffic to keep network access, shall be agreed with Tele2.

• Why: Unnecessary network signalling shall be avoided.

The IoT Solution’s specific traffic and signaling behavior shall be agreed with Tele2.

• Why: The device’s implemented network communication behavior affects it’s impact on network resources, e.g. having many short sessions or very long sessions with little data shall be avoided.

SMS shall not be sent in an uncontrolled manner to devices that cannot receive SMS by any reason. Maximum 5 expired SMS for one day or 20 expired SMS for one week per single device is accepted.

• Why: Uncontrolled traffic occupies capacity in the network and shall be avoided.

Efforts shall be made to minimize the number of Call Detail Records generated per account to an average of 300 CDRs per month and device.

• Why: Unnecessary CDRs creates additional load on connectivity management and mediation systems.

Standard Compliance

Devices shall be compliant with the latest GSM and UMTS standards from 3GPP and recommendations from GSMA

• Why: Only devices where the manufacturer certifies that GSM/UMTS standards are followed shall be used. Devices that do not follow standards may not work properly in the networks and run a greater risk of having problems as the networks develop over time.

Maintainable Solution

Device-OTA: Functions controlling network communication in the device and modem shall be possible to update via mobile network communication

• Why: If the devices network communication is erroneous and have a negative impact on the network, it is important that it’s functionality can be promptly corrected.

SIM-OTA: The device shall allow Tele2 to update SIM card parameters over the network

• Why: Over time, Tele2 needs to update software and parameters on the SIM cards in order to maintain a well working communication solution. This is done via the mobile network by SIM-OTA. The devices must support SIM-OTA and have it activated for the SIM cards to receive the information.

The customer shall be able to restart the device promptly

• Why: Restart of modem is necessary to trigger the clear FPLMN (Forbidden Public Land Mobile Network) application on the SIM cards and may also be necessary to make the device leave a dead-lock state.
• N.B. it is very important that the devices are not restarted at the same time in order to avoid synchronized behavior.

The M2M Solution shall be able to handle network maintenance

• Why: Although mobile networks have a very high availability, there will be time when parts of or the entire mobile network is out-of-order. The device shall in such a case be able to reconnect when the network is available again.
• N.B. Reconnecting to the network shall be done using an acceptable retry policy.

The IoT Solution shall be able to handle that allowed networks may change

• Why: Over time the networks that the device is allowed to use may change due that your requirements change and due that the Tele2 partner networks may change. The device must be able to reconnect when the allowed networks have changed.

Critical Device Risk Awareness

The customer should ensure a redundant connectivity solution

• Why: For Telecare and similar life and/or mission critical applications, it is essential to secure maximum service reliability and to avoid interruptions. Therefore, Tele2 strongly recommends implementing a redundant communication setup, such as dual SIM, mobile + Wi-Fi, or mobile + Ethernet. This safeguards the solution from single points of failure and ensures continuous operation, even if one connection fails.
• By choosing to use a single connectivity solution without redundancy, the customer accepts and acknowledges the risks associated with such a setup during mobile network service interruptions, that can result in the availability of the service being impaired, including the potential impact on the end user.

Quality Assurance

All changes to device and modem firmware shall be tested in a secure environment before release. The tests shall, at least, secure that the Network Communication Policy is followed.

• Why: New releases to the device and modem firmware may affect the network communication behavior and an erroneous release may have negative impact on the network if released to a large set of devices.

The customer shall inform Tele2 of planned releases that might affect the network communication behavior

• Why: By being informed of planned releases, Tele2 can support by providing known issues, agreeing on changed network communication behavior as well as detecting and diagnosing problems earlier.

Impact of Non-Compliance to Network Communication Policy

Termination of solution

• Tele2 reserves the right to terminate whole or parts of the IoT solution due to non- compliance with the Network Communication Policy.

Charge of unexpected costs

• Tele2 reserves the right to charge for any unexpected cost that may occur due to non-compliance with the Network Communication Policy.

Further Recommendations

Further written documentation

• Connected Device Developer Guidelines and Common AT Commands document, available in Tele2 IoT Control Center.

Professional services

• Contact your Tele2 representative for further information on how Tele2 IoT can assist you!

Definitions

• IoT Solution – includes the devices, servers and other components that directly or indirectly uses the mobile network for communication.
• Device – includes modem, application layer and other parts that are distributed to the end-points communicating with the network.
• Modem – the GSM/UMTS appliance that allows the device to communicate over the mobile network.
• Telecare – a subsection within IoT healthcare that primarily deals with life-critical applications and business operations.

For any further questions, please reach out to your Account Manager in Tele2 IoT or contact us here.