2. Samsung Telecommunications America Copyright 2003, STA, All Rights Reserved. 1 Format for Base Station Assigned PLCM Samsung Electronics Purva R.Rajkotiaprajkoti@sta.samsung.comprajkoti@sta.samsung.com Daegyun Kimdaegyun@samsung.comdaegyun@samsung.com B.S.Baebsbae@samsung.combsbae@samsung.com Samsung Electronics 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. Samsung Electronics 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 Samsung Electronics 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 Samsung Electronics. Samsung Electronics specifically reserves the right to amend or modify the material contained herein and to any intellectual property of Samsung Electronics other than provided in the copyright statement above.

3. Samsung Telecommunications America Copyright 2002, STA, All Rights Reserved. Dallas Telecommunications Lab Wireless Systems Lab 2 Introduction © SWG2.3 agreed to have Base Station Assigned PLCM as one of the techniques for assigning the PLCM. The Base Station Assigned PLCM, currently lacks the format definition. Several proposals [1],[2],[3] were submitted suggesting the different formats for PLCM. © Samsung believes that 3 main criteria should be satisfied for any proposal to be effective. High Level User Security Low Level of Collision Probability Easier for Implementation. In this contribution Samsung suggests a simpler, unique format for the Base Station Assigned PLCM, which satisfies all the above conditions.

4. Samsung Telecommunications America Copyright 2002, STA, All Rights Reserved. Dallas Telecommunications Lab Wireless Systems Lab 3 Format for BS- Assigned PLCM Longitude LatitudeMS Id 7 bits 3 bits Bits to distinguish between private/public long code masks and to differentiate between the MEID generated PLCM and BS- Assigned PLCM 7 bits25 bits BASE_LONG >> 8 mod [2^7]. MS Id assignment is left to the vendor’s implementation. An example of MS Id assignment could be MEID based or as simple as straight assignment by Base Station.

5. Samsung Telecommunications America Copyright 2002, STA, All Rights Reserved. Dallas Telecommunications Lab Wireless Systems Lab 4 Format for BS-Assigned PLCM © Longitude : The longitude is derivation of the BASE_LONG transmitted in the SPM. Longitude = (BASE_LONG >> 8) mod [2 ^ 7)]. © The longitude field is the base longitude in units of 64 seconds, converted into a 7 bit number. © Latitude : The base latitude is the derivation of the BASE_LAT transmitted in the SPM. Latitude = (BASE_LAT >> 8) mod[2 ^7)]. © The latitude field is the base latitude in units of 64 seconds, converted into a 7 bit number.

6. Samsung Telecommunications America Copyright 2002, STA, All Rights Reserved. Dallas Telecommunications Lab Wireless Systems Lab 5 Format for BS-Assigned PLCM © MS_id : The MS_id field is a 25-bit field assigned to distinguish mobile. The generation of the bits to be sent in the MS_id is left to implementation. ( It could be IMSI_based, MIN based or could be as simple as some number assignment by the Base Station). © The latitude and the longitude formula could be generalized as follows: Longitude = (BASE_LONG >> r) mod [2 ^ (d-r)]. Latitude = (BASE_LAT >> r) mod [2 ^ (d-r)]. Where R = 2 ^ r (0.25 seconds of longitude/latitude). R = diameter of the cell D = 2 ^ d (0.25 seconds of longitude/latitude). D = reusable distance

7. Samsung Telecommunications America Copyright 2002, STA, All Rights Reserved. Dallas Telecommunications Lab Wireless Systems Lab 6 Relation between the Diameter and the Re-usable Distance Number of bits ( r ) Diameter of a cell ( R ) Reusable distance (PLCM uses 7 bits for longitude/latitude value) ( D ) where d = 7 + r Reusable distance (PLCM uses 8 bits for longitude/latitude value) ( D ) where d = 8 + r 60.32 miles40.96 miles81.92 miles 70.64 miles 81.92 miles163.84 miles 81.28 miles 163.84 miles 327.68 miles 92.56 miles327.68 miles655.36 miles

8. Samsung Telecommunications America Copyright 2002, STA, All Rights Reserved. Dallas Telecommunications Lab Wireless Systems Lab 7 Collision and User Level Security © Collision is near to zero. The latitude and longitude fields used in the PLCM will not get repeated within 164 miles. Even beyond 164 miles, the collision probability is minimized b’coz of large number of unique ids. User Level Security. In a cell, there could be 32 million unique ids, hence presents a very highly secure and robust system.

9. Samsung Telecommunications America Copyright 2002, STA, All Rights Reserved. Dallas Telecommunications Lab Wireless Systems Lab 8 Advantages of the Proposal Very Simple to implement –The suggested format includes the information available at the Base Station. No need of any special or intensive algorithms. Unique Identification –The suggested technique, since it uses the Base Station Latitude and Longitude information, which are unique, will result in an unique identifier. No need of soft/softer handoff mechanism change. (Refer Appendix). –Since the format can be transmitted from one base station to another without the fear of collision, no newer techniques or changes required to support soft/softer handoff. PLCM assignment is independent of network/vendor. No issue regarding the inter-operability. No burden of management on the carriers. Minimal Changes required in the Standards.

10. Samsung Telecommunications America Copyright 2002, STA, All Rights Reserved. Dallas Telecommunications Lab Wireless Systems Lab 9 Advantages of the Proposal No interoperability issues –The format suggested is independent of the network, geographical region. Since the format is independent, there are no inter-operability issues. Flexible Proposal Can work will all kinds of network architecture. –PLCM assignment done at the BTS level. No impact to the mobile station design. Close to zero probability of collision.

11. Samsung Telecommunications America Copyright 2002, STA, All Rights Reserved. Dallas Telecommunications Lab Wireless Systems Lab 10 References © [1] C23-20030217-023B(QCOM-PLCM Management) © [2] C23-20030522-0xx – LGE- IMSI based PLCM generation. © [3] C23-20030609-001 LG Electronics LGE Method PLCM Gen

12. Samsung Telecommunications America Copyright 2002, STA, All Rights Reserved. Dallas Telecommunications Lab Wireless Systems Lab 11 Appendix- Soft/Softer Handoff The PLCM is assigned by the anchor BS, which is used by the mobile station throughout the call, as long as the mobile performs soft/softer handoff. This PLCM will be retained –even if no leg is currently assigned on the anchor Base Station, (anchor Base Station leg drops) as long as there is no change in SDU.

13. Samsung Telecommunications America Copyright 2002, STA, All Rights Reserved. Dallas Telecommunications Lab Wireless Systems Lab 12 Appendix - Soft/Softer Handoff SDU BS1(Anchor BS)BS2 BS3 t0t0 t1t1 t2t2 t3t3

14. Samsung Telecommunications America Copyright 2002, STA, All Rights Reserved. Dallas Telecommunications Lab Wireless Systems Lab 13 Appendix –Soft/Softer Handoff © t 0 – Call is established in BS1. © t 1 – MS is in soft handoff with BS1 and BS2 © t 2 – MS has dropped BS1. MS is tuned only to BS2 © t 3 – MS is soft handoff with BS2 and BS3. © All the times Anchor BS (BS1) is SDU. © Anchor BS request to use the assigned PLCM to the target BS(s) during soft handoff leg establishment. © Target BS may reject the requested PLCM if the same PLCM is already in use in the target BS. This may trigger PLCM change. © When call is released on BS3 (though no leg is present with BS1), BS1 is aware (since the SDU is with the source BS- BS1),it releases the SDU and the PLCM.