• UMTS - the most common and used for today's 3G UMTS phones
• CDMA - applies to 3G CDMA femtocells compatible with 3G CMDA phones
• IMS - scheduled for inclusion in 3GPP Release 10, this will use the SIP/IMS core network and be backward compatible with existing phones

This connects into the operator's core network using the same Iu interface that existing outdoor cellsites use. Femtocells also conform to the standard radio transmission frequencies and protocols used today.

The mobile operators telephone switch (MSC) and data switch (SGSN) also communicate to the femtocell controller in the same way as other mobile calls. Therefore, all services including phone numbers, call diversion, voicemail etc. all operate in exactly the same way and appear the same to the end user.

The femtocell appears to the standard 3G phone as just another cellsite from the host mobile operator, and can be used by almost any phone including roamers visiting from other countries.

The connection between the femtocell and the femtocell controller is termed the Iu-h interface and it uses a secure IP encryption (IPsec) to avoids interception. There is also authentication of the femtocell itself to ensure it is a valid access point.

The femtocell connects over broadband IP with a femto-gateway which may handle hundreds of thousands of femtocells. These are consolidated into a single Iu interface which can carry thousands of concurrent calls and data sessions.

The standardisation of the Iu-h interface was included in the 3GPP Release 8 standard which will receive formal approval during Q1 2009.

Comments (2)

RAJESH said:

	About FEMTO CELL Hello, i 'm pursuing my Engineering degree in final year in INDIA n thought to implement femto cell as a mini project in our course. what do you say about this??
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January 23, 2010
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Thinkfemtocell said:

Quite a challenge I also did an Engineering Degree including a final year project some time ago. While you might want to do something novel, building a complete femtocell seems to be a much larger task - most femtocell vendors have large teams of engineers working on this. You may also need to get special permission from your regulator to broadcast on test frequencies. Perhaps instead you could look at creating a femtocell application (especially if it didn't need a real femtocell for demonstration purposes). Another option might be to look at extending or contributing to the OpenBasestation.org project to build an open source GSM basestation. Good luck.

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January 25, 2010
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