15-16 october 2007, 3gpp2 tsg-s femto cell workshop femto cell service requirements and issues...

15-16 October 2007, 3GPP2 TSG-S Femto Cell Workshop

Femto Cell Service Requirements 　 and Issues

Norikazu （ Nick ） Yamasaki Ryuhei 　 Munakata

KDDI Corporation


Benefits of Femto Cell Deployment

1 ． Improvement of Indoor Coverage and Capacity

　　　　 -Supplement of Macro Cell (high-rise apartment / 　　　　　　 building, home and office out of macro cell

coverage) 　　　　 -Improvement of Users’ Convenience

2. Offloading Macro Cell Traffic to Femto Cell-More than 50% of busy-hour traffic originating from 　 residences and increasing-Homes with broadband Internet connection rapidly increasing-Operators can increase system capacity. Leads to more efficient frequency utilization.

3 ． Acceleration of Fixed/Mobile Convergence


IP Based Network

Mobile Macro Network

Macro Cell

Femto Network

Equipment

Subscriber’s home

Outdoor

Indoor : Femto Cell

Outdoor : Macro Cell

Same Handset available both outdoor and

indoor

Femto Cell AP

Basic Concept of Femto Cell Service

Subscriber’s Broadband

Circuit

415-16 October 2007, 3GPP2 TSG-S Femto Cell WorkshopPopulation Density

Large

SmallLow High

Bu

ild

ing

S

ize

Redevelop-ment Project a

rea,Event Site

Redevelop-ment Project a

rea,Event Site

Small ShopSmall Office

Home Office

Small ShopSmall Office

Home Office

Super Market

Restau-rant

Super Market

Restau-rant

Shopping Center,Office,

Subway,Under-ground Shoping Center

Shopping Center,Office,

Subway,Under-ground Shoping Center

Residence

Residence

Apartment

Apartment

Rural AreaRural Area 　 Urban Area　 Urban Area

Indoor

Outdoor

Femto CellFemto Cell

Target Area of Femto Cell Deployment


General Requirements for Femto Cell Standardization

1. Services and Functionality

(1) Support all the features and services of legacy CDMA1X/HRPD via Macro Cell

(2) Support 1X CS Voice Call

(3) Consideration for future VoIP Services

(4) Need to support BCMCS

2. Interference Management

Need mechanism to control and minimize interference with Macro Cell and other Femto Cell 　→　 Easier to use the frequency band which is not used for Macro Cell?

3. Mobility Management

Mobility management with Macro Cell is desirable. However, if there is any impact on cost and standardization schedule,

operators should be able to select specific functions for implementation.


Issues on System Selection

1. System Selection function is definitely needed for Femto Cell services.

2. No modification on existing handset (manageable by network implementation is

desirable).

3. Must determine the most effective System Selection method from Macro Cell to Femto Cell (for example: Manual switching function using scanning search for the Femto

frequency)


System Synchronization Issue

・　 System synchronization of CDMA2000 is fully based on GPS.

- Current Interference Management system is dependent on GPS signal reception.

・　 In Japan,

　 - Difficult to receive GPS signal in house (especially reinforced concrete type apartment/building)

- Difficulty in cabling in the case of external antenna

Therefore:

1. Need to develop new system synchronization method other than GPS

2. Need to develop effective interference management system which is working when GPS signal is not available


HRPD/1xHRPD/1x

Femto AP

FNG

PDSN

CallManager

PCF/RAN

A1/A2

A10/A11

SIP

SIP

Possible Network Architectures

HLRHRPD/1xHRPD/1x

Femto AP

FNG

PDSN

PCF/RAN

A10/A11

SIP

SIP

IS-41

IMSIMS

HLR

The figures below are example of Network Architecture to provide CDMA Service continuously even in the Femto Areas without impact on Legacy CDMA systems.

MSC

Fig.1: use current Circuit Switch system Fig.2: introduce IMS system for Voice Service


Requirements on Workplan

1. Best Case Completion of Standardization for Femto Cell

(1) Completion by Mid 2008

(2) Phased approach should be considered.

　　　 Initial phase : Minimum set (less options)

2. Handover between Femto and Macro Cells　 Mobility management function with Macro Cell is desirable. However, if there is any impact on cost and standardization schedule, operators should be able to select specific functions for implementation. In this regard, this Handover between Femto and Macro Cells function should be an optional requirement in specification, or phased approach is needed.

3. Issues that Must Be resolved

(1) System Selection Function

(2) System Synchronization


Thank you!Thank you!

15-16 october 2007, 3gpp2 tsg-s femto cell workshop femto cell service requirements and issues...

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