Over the last few days, iPhone users who subscribe to the popular Kolbi wireless carrier in Costa Rica have noticed that they can no longer navigate the Web or use some apps and simultaneously manage a voice call. The crux of this technical issue is that 3G access seems to goes away when a connection is made to another wireless phone or to a data source.

 

According to technology blog iPhoneti.co, the quality of voice calls for the iPhone in Costa Rica has also dropped noticeably in recent weeks. This suggest that Kolbi, which is managed by the former telecommunications monopoly ICE, is forcing all voice calls to downgrade to the old 2G network and leaving the 3G network to exclusively handle wireless data connections.

 

The above situation is known as an Inter Radio Access Technology (iRat!) handover, which –according to RFWireless-Word.com:

 

an be either GSM, CDMA, WiMAX, LTE, TD-SCDMA or any other wireless technology used to provide air interface to mobile to obtain various services (voice, email, Internet, VOIP).

 

IRAT is mainly used for handover between different RAT. Mobile terminal while in one RAT performs neighbour cell measurements and sends measurement report to the network. Based on this measurement report provided by mobile terminal, network can initiate handover from one RAT to the other RAT. This is called IRAT handover.

 

Since it seems that IRAT handovers are being utilized by Kolbi to manage iPhone communications in Costa Rica, it could be assumed that ICE is trying to alleviate or otherwise manage wireless network saturation; the problem is that it is being done at the sacrifice of being able to access the Internet and conducting voice calls at the same time. Other iPhone users are also reporting frustration when using Siri, Apple’s nifty personal assistant, which seems to be out of commission for all iPhone users who subscribe to 4G LTE data packages.