37 Femtocell deployments in 23 countries

Growing number of operators are committing to LTE small cell deployments which are expected to form a key market trend in 2012, said a recent Informa Telecoms & Media femtocell market status report.

There are currently 37 commercial deployments with regional US operator, Mosaic Telecom, being the latest to deploy femtocells. Telecom Italia announced its plans to launch before the end of the year and SK Telecom revealed it is set to launch the world’s first LTE femtocell service. Furthermore, Telefonica O2 has disclosed pre-launch details of its ‘Boostbox’ femtocell service in the UK for both consumers and enterprises. Separately, a number of deployed operators have passed 100,000 units, demonstrating the scalability and mass-market appeal of the technology.

Over the past quarter, Sprint, the first operator to deploy femtocells, announced it has rolled out 500,000 units and expects to exceed 1 million by 2013. With AT&T constituting the world’s largest femtocell deployment, it is clear that the US continues to be the most mature small cell market. However, several European and Asian operators including Vodafone UK, Japan’s Softbank and France’s SFR, announced they reached scale by surpassing 100,000 deployed units. Vodafone, which recently launched a marketing campaign around its UK femtocell offering, now offers femtocells in 12 countries and plans to deploy across the whole group.

Vodafone UK recently announced it is to offer public access rural femtocells that will be placed on BT telephone poles in order to bring coverage to “not spots” and areas where traditional base stations have not been economical. The report also highlights growing operator commitment to LTE femtocells with Verizon and Sprint announcing support in the past quarter and SK Telecom promising a commercial deployment before the end of the year. A previous survey conducted by Informa Telecoms & Media showed that 60% of operators believe small cells will be more important than macrocells in LTE networks.

CDMA operators continue to aggressively deploy femtocells with both Sprint and Verizon launching enterprise services which allow several femtocells to be linked together to cover large buildings. To assist CDMA operators, the Femto Forum and 3GPP2 recently published an operator guide detailing best practice for deployments.

There are now 37 femtocell deployments spanning 23 countries and 15 further operator commitments. In June 2011, Informa Telecoms Media estimated that there were in excess of 2.3 million femtocells active both privately in homes and offices, as well as publically in metropolitan and rural environments. As such, there are more 3G femtocells than conventional 3G base stations globally and Informa forecasts growth to continue with 48 million access points in use globally by 2014. Eight of the top 10 mobile operator groups (by revenue) offer femtocell services – this includes AT&T Group, France Telecom Group, NTT DOCOMO Group, Sprint, Telefonica Group, Deutsche Telecom Group, Verizon Wireless and Vodafone Group.

Local IP Access and IP Traffic Offload for Femtocells

3GPP has enhanced Local IP Access and IP Traffic Offload for femtocells in Release 10. Rel 9 only focused on Local IP Access to the home based network only while Rel 10 extends same to enterprise IP network as well.

LIPA (Local IP Access) provides access for IP capable UEs connected via a H(e)NB (i.e. using H(e)NB radio access) to other IP capable entities in the same residential/enterprise IP network.

Traffic for Local IP Access is expected to not traverse the mobile operator’s network except H(e)NB.

With Selected IP Traffic Offload (SIPTO), H(e)NB would support Selected IP Traffic Offload to provide access for a UE connected via a H(e)NB to a IP network e.g. Internet.

In 3GPP Rel-8 and Rel-9, 3GPP has specified functionalities for the support of H(e)NB. 3GPP had requirements on Local IP Access to the home and Internet in TS 22.220 but those features were not completed as part of Release 9.

3GPP Rel 10 extends LIPA requirements for H(e)NBs as followings, some of them already has been identified by Rel 9.

• Support of Local IP Access in order to provide access for IP capable UEs connected via a H(e)NB to other IP capable entities in the same residential/enterprise IP network.
• Support of simultaneous access from a UE to the mobile operator’s core network and Local IP Access to a residential/enterprise IP network
• Local IP Access traffic to be routable only between the UE, H(e)NB and other entities within the residential/enterprise IP network (subject to regulatory requirements).
• UE to have a valid subscription with the mobile operator in order to use Local IP Access.
• Use of Local IP Access in a visited network by UE to be subject to roaming agreement between mobile operators.
• The HPLMN to be able to enable/disable LIPA usage when the UE roams to particular VPLMNs.
• Local IP Access to be available for Pre-Rel 10 UEs as well.
• A UE using LIPA will be contactable by another IP endpoint in the same IP network via Local IP Access.
• UE to maintain its IP connectivity to the residential/enterprise IP network when moving between H(e)NBs within the same residential/enterprise IP network.
• The mobile operator can enable/disable Local IP Access per H(e)NB and per UE.
• Local IP Access will not compromise the security of the mobile operator’s network.

Selected IP Traffic Offload (SIPTO) for H(e)NB

H(e)NB can support Selected IP Traffic Offload to provide access for a UE connected via a H(e)NB to Internet. The following 3GPP requirements apply to support Selected IP Traffic Offload for H(e)NB SubSystem:

• Selected IP Traffic Offload to be possible to be done without traversing the mobile operator network, subject to regulatory requirements.
• The mobile operator and the H(e)NB Hosting Party, within the limits set by the mobile operator, shall be able to enable/disable Selected IP Traffic Offload per H(e)NB.
• Based on mobile operator SIPTO policies, the network shall be able to allow the user to accept/decline offload before the traffic is offloaded.
• The SIPTO policies may be defined per APN, per IP Flow class under any APN, or per IP Flow class under a specific APN.
• The mobile operator shall be able to configure the SIPTO policies either statically or dynamically.

HNBs in Enterprise Environments

HNBs are expected to be used in enterprises for business communication among permitted users. To allow easy integration into the enterprise's IT infrastructure, HNB needs to support additional functions e.g. Authentication and charging.

IP enabled UEs that are connected via HNBs to the enterprise IP network are expected to receive the enterprise's IP based services.

The following additional requirements apply for intended usage of HNBs in enterprise environments.

HNB may be able to route traffic to/from the enterprise's IP network without traversing the mobile operator’s core network, subject to regulatory requirements and agreement between the Mobile Operator and the Enterprise.

Local traffic routing applies to:

• Traffic between the UE and another UE under coverage of the enterprise's HNBs
• Traffic between the UE and entities in the enterprise IP network (e.g. when interworking with an IP- Private Branch Exchange (IP-PBX))

According to 3GPP specification, it may be possible to support interworking with an enterprise's existing voice and multimedia services (e.g., (IP-PBX). In particular UEs under coverage of the enterprise's HNBs may be able to participate in interactive communication services offered by the IP-PBX.

Source: LteWorld

Local IP access to home based network & Internet via HNB/HeNB

3GPP specfications has specified requirements for Local IP access via femtocell access nodes ie. 3G HNB & LTE HeNB. HNB and eHNB are Customer-premises equipments (femtocell) that connect a 3GPP UE over UTRAN and EUTRAN wireless air interface respectivly to a mobile operator’s network using a broadband IP backhaul.

This is an added advantage and driver for end users to have a femtocell in home. Users would be able to access local IP devices and Internet without going through operator's network.

As per specifications Local IP Access to the home based network provides access for a directly connected (i.e. using H(e)NB radio access) IP capable UE to other IP capable devices in the home.

Further 3GPP adds that it would be possible to access Internet using local IP network also.

Traffic for local IP access is expected to not traverse the operator’s network except H(e)NB.

A logical diagram is shown below for Local IP access

A summary of requirements set by 3GPP for HNB & HeNB to support Local IP Access are as below

• Support of simultaneous access from a UE to both the operator’s core network and Local IP Access to the home based network/Internet
• Support of Local IP Access to the home based network/Internet without traversing the operator’s network except H(e)NB
• The operator or the H(e)NB Owner, within the limits set by the operator would be able to enable/disable Local IP Access to the home based network/Internet per H(e)NB.
• It would be possible to collect and make available to the operator statistics information (e.g. regular reporting of Local IP traffic volume) for each user on the use of the Local IP Access to the home based network/ Internet.
• Local IP access to home based network/ Internet would not compromise the security of the operator’s network.

Local IP access to home based network would also be possible through the H(e)NB E-UTRAN/UTRAN-interface as well however It will only be granted to UE with valid subscription.

For further readings 3GPP specification 22.220 can be referred.

Femtocell - News, Video & Whitepapers

LteWorld has recently added a new page with Femtocell news, videos & whitepapers. Page is available here.

A Femtocell is a device used to improve mobile network coverage in small areas. Femto cells connect locally to mobile phones and similar devices through their normal GSM, GPRS, or UMTS connections, and then route the connections over a broadband internet connection back to the mobile network, bypassing the normal cell towers.