All Rights Reserved © Alcatel-Lucent 2007

SOURCE: Dennis Ong, Alcatel-Lucent John Burgess Alcatel-Lucent

CONTACT: hdong@alcatel-lucent.comjkburgess@alcatel-lucent.com

ABSTRACT: This contribution discusses where we are with IS-2000 3G1x Femto system selection, and what we need to look for in a solution.

TITLE: Femtocell System Selection

3GPP2 Femto Cell Workshop

RECOMMENDATION: <Discuss / FYI >

Alcatel-Lucent grants a free, irrevocable license to 3GPP2 and its Organizational Partners to incorporate text or other copyrightable material contained in the contribution and any modifications thereof in the creation of 3GPP2 publications; to copyright and sell in Organizational Partner's name any Organizational Partner's standards publication even though it may include all or portions of this contribution; and at the Organizational Partner's sole discretion to permit others to reproduce in whole or in part such contribution or the resulting Organizational Partner's standards publication. Alcatel-Lucent is also willing to grant licenses under such contributor copyrights to third parties on reasonable, non-discriminatory terms and conditions for purpose of practicing an Organizational Partner’s standard which incorporates this contribution.This document has been prepared by Alcatel-Lucent to assist the development of specifications by 3GPP2. It is proposed to the Committee as a basis for discussion and is not to be construed as a binding proposal on Alcatel-Lucent. Alcatel-Lucent specifically reserves the right to amend or modify the material contained herein and to any intellectual property of Alcatel-Lucent other than provided in the copyright statement above.

S00-FEMTO-20070915-008<Femtocell System Selection>

All Rights Reserved © Alcatel-Lucent 20072 | October 15-16, 2007

Technical Discussion: System Selection

How does an IS-2000 mobile find the Femto? Depending on deployment, same carrier or dedicated carrier

Most cases will behave like dedicated carrier, since the Macro will typically have more carriers than the Femto

Idle mode General Neighbor List (GNL) message on Macro has frequency information

of Femto neighbors As long as the Femto EC/I0 is 3dB stronger than the Macro EC/I0, the IS-2000

mobile will perform the idle hand-off If the Femto is located too close to an unloaded Macro, this condition may

fail Active mode (future)

Macro can direct mobile to search other frequencies using Candidate Frequency Search (CFS)

IS-95 (pre-IS-2000) 2G mobiles cannot receive either the GNL or CFS message, will not be able to find most Femtos Femto on dedicated carrier, or Femto on macro carrier, not the one hashed to by 2G mobile

All Rights Reserved © Alcatel-Lucent 20073 | October 15-16, 2007

Technical Discussion: System SelectionWhere is the Femto is located too closely to Macro, key to colors

Direct Line-of-Sight

-1000 -500 0 500 1000-1000

-800

-600

-400

-200

0

200

400

600

800

1000

x [m]

y [m

]

Pmacro = 16W, rmacro = 1033m, Pfemto,max = 50mW, Channel: freespace

femtocells that achieve target rangereduced range (34.8%)reduced range: 15dB macro & 7.5dB femto wall sep. (6.2%)reduced range: 15dB macro wall separation (1.1%)

Femto Achieves Full Range (Blue)

Femto Reduced Range (no penetrationlosses)

Femto Reduced Range, penetrationLosses:15dB external wall for Macro 7db internal wall for Femto

Femto Reduced Range, penetrationLosses: 15dB external wall for Macro

All Rights Reserved © Alcatel-Lucent 20074 | October 15-16, 2007

Technical Discussion: System Selection

Where is the Femto is located too closely to Macro? Urban Direct Line-of-Sight

Femto 50 mW

PCS 16W Half the size of

Cellular cell below

Cellular 20W

-1000 -500 0 500 1000-1000

-800

-600

-400

-200

0

200

400

600

800

1000

x [m]

y [m

]

Pmacro = 16W, rmacro = 1033m, Pfemto,max = 50mW, Channel: typical urban

femtocells that achieve target rangereduced range (1%)reduced range: 15dB macro & 7.5dB femto wall sep. (0.4%)reduced range: 15dB macro wall separation (0.1%)

-1000 -500 0 500 1000-1000

-800

-600

-400

-200

0

200

400

600

800

1000

x [m]

y [m

]

Pmacro = 16W, rmacro = 1033m, Pfemto,max = 50mW, Channel: freespace

femtocells that achieve target rangereduced range (34.8%)reduced range: 15dB macro & 7.5dB femto wall sep. (6.2%)reduced range: 15dB macro wall separation (1.1%)

-2000 -1500 -1000 -500 0 500 1000 1500 2000

-2000

-1500

-1000

-500

0

500

1000

1500

2000

x [m]

y [m

]

Pmacro = 20W, rmacro = 2321m, Pfemto,max = 50mW, Channel: typical urban

femtocells that achieve target rangereduced range (0.2%)reduced range: 15dB macro & 7.5dB femto wall sep. (0.1%)reduced range: 15dB macro wall separation (0%)

-2000 -1500 -1000 -500 0 500 1000 1500 2000

-2000

-1500

-1000

-500

0

500

1000

1500

2000

x [m]

y [m

]

Pmacro = 20W, rmacro = 2321m, Pfemto,max = 50mW, Channel: freespace

femtocells that achieve target rangereduced range (8.6%)reduced range: 15dB macro & 7.5dB femto wall sep. (1.3%)reduced range: 15dB macro wall separation (0.3%)

All Rights Reserved © Alcatel-Lucent 20075 | October 15-16, 2007

Technical Discussion: System Selection

Where is the Femto is located too closely to Macro? Countryside Direct Line-of-Sight

Femto 50 mW

PCS 16W Half the size of

Cellular cell below

Cellular 20W

-5000 0 5000

-5000

-4000

-3000

-2000

-1000

0

1000

2000

3000

4000

5000

x [m]

y [m

]

Pmacro = 16W, rmacro = 5790m, Pfemto,max = 50mW, Channel: countryside

femtocells that achieve target rangereduced range (0%)

-5000 0 5000

-5000

-4000

-3000

-2000

-1000

0

1000

2000

3000

4000

5000

x [m]y

[m]

Pmacro = 16W, rmacro = 5790m, Pfemto,max = 50mW, Channel: freespace

femtocells that achieve target rangereduced range (1.4%)reduced range: 15dB macro & 7.5dB femto wall sep. (0.2%)reduced range: 15dB macro wall separation (0.1%)

-1 -0.5 0 0.5 1

x 104

-1

-0.8

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

0.8

1x 10

4

x [m]

y [m

]

Pmacro = 20W, rmacro = 10118m, Pfemto,max = 50mW, Channel: countryside

femtocells that achieve target rangereduced range (0%)

-1 -0.5 0 0.5 1

x 104

-1

-0.8

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

0.8

1x 10

4

x [m]

y [m

]

Pmacro = 20W, rmacro = 10118m, Pfemto,max = 50mW, Channel: freespace

femtocells that achieve target rangereduced range (0.3%)reduced range: 15dB macro & 7.5dB femto wall sep. (0%)

All Rights Reserved © Alcatel-Lucent 20076 | October 15-16, 2007

Technical Discussion: System Selection

How to improve the success of idle IS-2000 mobiles finding the right Femto? Without changing the standards or the mobiles

Add Femto beacon pilot on some or all MacroCell Carriers (hopping or not) Will need more than just a pilot to direct idle mobiles to the right carrier

Pros 2G mobiles may find the

Femto MacroCell NL population may

be easier Can allot fewer PN offsets if

Femto main carrier spread over multiple carriers

Cons RF Interference on multiple

carriers FemtoCell cost increases from

additional radio hardware Better chance for mobiles to

idle hand-off to Femtos that do not allow them access

All Rights Reserved © Alcatel-Lucent 20077 | October 15-16, 2007

Technical Discussion: System Selection

How to improve the success of idle IS-2000 mobiles finding the right Femto? Allowing changing the standards and the mobiles

Airvana’s Preferred User Zone List (PUZL) changes

Pros Mobile finds the allowed

Femtos without guesswork Mobile does not spend much

time idling on unavailable Femtos

Cons Will require changes to the air

interface, mobile & network New P_REV

“Black list” may be difficult to maintain at the Macro

All Rights Reserved © Alcatel-Lucent 20078 | October 15-16, 2007

Technical Discussion: System Selection

IS-2000 mobile/Femto system selection still needs more thinking Prefer solutions that do not change the air interface Need a solution for the “exclusion zone”

Especially when there are calls on the Femto

Willing to entertain other solutions ALU working on alternate solutions not yet ready for publication