Cell_Reservation_Access_Restrictions

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Cell Reservation Access Restrictions

标签（空格分隔）： Cell_Reservation SIB3 SIB4

0.概述

在UTRA cells主要是两种机制来设置Cell reservation或者Access restrications. - 限制当前cell reservation状态来控制cell selection和cell reselection; - 透过显示Access Class来控制和限制不同class的用户来发起不同的服务;

无论上述哪种机制，都需要透过小区的系统消息3或者系统消息4来广播当前cell reservation状态，如下：

CellAccessRestriction ::=			SEQUENCE {
	cellBarred							CellBarred,
	cellReservedForOperatorUse			ReservedIndicator,
	cellReservationExtension			ReservedIndicator,
	-- NOTE: IE accessClassBarredList should not be included if the IE CellAccessRestriction
	-- is included in the IE SysInfoType4
	accessClassBarredList				AccessClassBarredList				OPTIONAL
}

如果是第二种机制，还需要从USIM卡中获取当前卡的Access control class(EFacc)信息, 参考TS 22.011 Service accessibility.

1.Cell Reservation

  • 认识IE:
    • CellBarred CellBarred ::= CHOICE { barred SEQUENCE { intraFreqCellReselectionInd AllowedIndicator, t-Barred T-Barred }, notBarred NULL }
    • cellReservedForOperatorUse
    • cellReservationExtension ReservedIndicator ::= ENUMERATED { reserved, notReserved }
    • Tbarred：单位应是miliseconds. T-Barred ::= ENUMERATED { s10, s20, s40, s80, s160, s320, s640, s1280 }
  • Overview:

cellBarred|cellReservedForOperatorUse|cellReservationExtension|Action for Cell Selection or Cell Reselection|Tbarred -|-|-|-|-| Not Barred|Not Reserved|Not Reserved|No restriction|NA Not Barred|Not Reserverd|Reserved|1.若cellReservedForCSG 指示为ture，则认为该cell是 not reserved；2.其他状况，则认为该栏位是reserverd，所以该cell为barred,cell selection and reselection restrict except for ECC call|Tbarred Not Barred|Reserverd|NA|1.在HPLMNorEHPLMN的小区上，Access Class 11-15的UE仍可以正常Cell selection and Cell reselection;2.其他状况下认为该cell是barred，cell selection and reselection restrict except for ECC call|Tbarred Barred|NA|NA|1.不可以做cell selection and reselection,也不可以做ECC call;2.ignore cellReservationExtension;3. intraFreqCellReselectionInd为allowed,则可以cell selection/reselection到intraFreqCell上.如果选到其他Cell上了，那么等待Tbarred expiry要将barred cell从barred cell list中剔除。如果并没有选到其他Cell上，而是在原来Cell上那么等待Tbarred expiry后需要check当前cell barred状态是否更正。4.如果intraFreqCellReselectionInd为not allowed，那么无法进行同频小区的cell selection/reselection.在原来Cell上那么等待Tbarred expiry后需要check当前cell barred状态是否更正. 补充：关于ECC call在Cell barred的时候是无法拨打的，但如果当前Cell barred是因为restrictions due to cell reservations,也就是cellReservedForOperatorUse和cellReservationExtension认为是Cell barred，那么是可以拨打ECC call.

2.Access Controls Class

Access Controls Class并不影响该Cell是否可以camp on而影响在该Cell上是否可执行某些业务，比如LU，RAU，比如ECC call等等. - Basic Version: - Access control class allocation: > 所有的UE(从卡中获取)都要随机分配Access Class 0-9,另外，还可以分配1个如下特殊class: Class 15 - PLMN Staff; -“- 14 - Emergency Services; -“- 13 - Public Utilities (e.g. water/gas suppliers); -“- 12 - Security Services; -“- 11 - For PLMN Use.

  • Operation: > 系统消息3和系统消息4中会广播access class,如果卡中相对应的class被置为1，那么说明该class是被允许接入的，如下是class的受用范围： Class|field -|- Classes 0 - 9|Home and Visited PLMNs; Classes 11 and 15|Home PLMN only if the EHPLMN list is not presentor any EHPLMN; Classes 12, 13, 14|Home PLMN and visited PLMNs of home country only. For this purpose the home country is defined as the country of the MCC part of the IMSI. Any number of these classes may be barred at any one time.

  • Emergency Call: > Acess Class 10指示是否可以拨打ECC call, 当该栏位指为1表明，class是0-9的UE以及没有SIM卡的有UE都可以拨打ECC call。然而, 如果是Class 11-15的UE，当Class 11-15被禁同时Access Class10被禁时才会被限制拨打ECC call.其他状况下，均可以拨打ECC call.

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