The swappable SIM card was one of the original attributes of GSM trumpeted by users and operators as an advantage over CDMA. The logic went that a removable SIM allowed users to swap hardware without needing to contact their operator and made the address book portable. This was particularly useful for corporate clients managing break/fix and hardware migrations as well as anyone who suffered equipment failure or was upgrading devices. CDMA carrier customers on the other hand had to call customer care and manually make the switch with a customer service representative; deally no digits were misread, typed incorrectly, and the over the air provisioning (OTA) was successful. These were simpler times and data services were just coming online around the late 90s and the beginning of the next decade.

Leap forward to 2012 and the experience of a Verizon Wirless or Sprint customer vis-a-vis AT&T Wireless customer appears to have reversed. Today CDMA subscribers of many operators, Sprint and Verizon Wireless included, can simply visit their online account management tool, enter the ESN or IMEI and swap devices. This is not to trivialize the backend processes that the carrier must coordinate between the billing, provisioning, and network resources to assure proper billing subscriptions are applied, network resources are allocated (e.g. Home agent etc.), and services function properly. In a world of 3G, 4G, application billing, and soon class and priority of service any misstep disrupts the customer experience and drives calls to customer care.

The nature of CDMA has long required that the devices ESN be preloaded for the network provisioning and resources to validate and recognize the device. In this way the CDMA devices were already bootstrapped and ready for OTA provisioning. GSM networks instead relied on a valid SIM to handle authentication and transmission of the IMEI to the network operator. Bootstrapping was either accomplished at the factory and the proper APN, MMS, etc. setting were then updated silently through USSD, WBXML, etc. or a similar user initiated or approved update was applied. These processes continued to evolve and become more sophisticated with the evolution and standardization of OMA-DM and FOTA protocols and services. In short GSM providers that have migrated to HSPA and now LTE can automatically recognize devices, apply proper billing codes, and push necessary settings with little or no user intervention for devices that at factory bootstrapped or come from outside supply channels even in this far more complex world.

Considering all of these technical capabilities it was not possible on January 21, 2012 to take a AT&T Wireless SIM from a HP Palm Pre 2 and use it with a brand new AT&T Sony Ericsson Xperia Play. The Xperia Play recognized the SIM, attached to the AT&T 3G HSPA network and received a welcome AT&T SMS message. Voice and SMS services were tested and functional however data services were not accessible. The Xperia Play's APNs were correct yet it would not establish a data session.

Based on the previously mentioned functionality it can be inferred that the device and SIM successfully communicated with the AT&T AuC, HLR, SMSC, etc. but not to the SGSN. The online billing system confirmed that a 2 GB PDA/smartphone data plan was provisioned eliminating the binary question of whether data services should be accessible. The possibility certainly did exist that an identical feature set data plan but with a different billing code could be needed. If this was the case AT&T's billing system should have received the information from the AuC, HLR, etc and made the proper switch. Before calling customer care I thoroughly searched AT&T's self management portal for a self service IMEI registration to no avail. It's worth noting that this subscription is attached to a larger national foundation account for individual liable accounts versus a simple standalone consumer account.

Once I reached technical support a representative manually took the Xperia Play's IMEI and confirmed that a different billing code was required. The plan's MRC remained the same as well as the included data and overage amounts it was just that a different code was required. To make matters worse the representative didn't want the IMEI form a *#06# query but instead from the sticker underneath the battery. This process added additional time and steps to the call that only appeared to increase the cost to AT&T and a customer's frustration.

Once the phone was power cycled it successfully attached to the data network and completed a data session. A quick check of the APN confirmed these were unchanged implying the issue resided within AT&T's systems and missed linkages between the IMEI capture, the billing systems, and service provisioning. This experience is not an isolated one and a similar amount of hooping jumping had to be done a year ago when swapping an AT&T SIM from an AT&T iPhone 4 to another iPhone 4. In that case SMS inbound services simply failed.

AT&T's inability to recognize devises and harmonize the billing and provisioning services of similar device classes creates a negative user experience and drives customer care costs. This is particularly important to note for organizations that are centrally managing mobility services and device fleets as it adds overhead to the operation and end user inefficiency. Even in a BYOD paradigm users seeking to swap a corporate supplied SIM to their own hardware will drive service escalations through the organization and then to the AT&T support staff serving the account.

There is also the scenario where the employee is liable for the service as well as uses a BYOD but the involvement of the corporate support desk is still likely. In this scenario the user still looks to the support desk, regardless of policy, to get their services running. The support desk can either reject the query or soft transfer the user to AT&T customer support. Either scenario still drives corporate costs, frustrates users, and drives a negative impression of AT&T.

These scenarios are not unique to AT&T and certainly other GSM/HSPA operators may face similar issues. This example illustrate the importance of the integration of network elements including billing and provisioning in a complex data services world. With the lack of differentiation in Android devices and users failing to differentiate between 3G, 4G, and LTE operators would be well served to improve the user experience with automatic device identification, provisioning, and billing. Until then I will probably have to call customer care again when my Nokia Windows Phone arrives....

Tags: AT&T Wireless