What is paging in LTE network?
Paging in LTE network is used to inform and notify UE about various events. The propose of paging procedure is: To transmit paging information to a UE in RRC_IDLE state. To inform UEs in RRC_IDLE and UEs in RRC_CONNECTED state about a system information change. To inform UE about ETWS primary notification and ETWS secondary notification.
What does Mme initiated paging mean?
MME initiated Paging. It means that paging can be initiate by MME and eNB. When there is a change in system information, the Paging message can be sent to UE even if it is in RRC_IDLE and RRL_CONNECTED mode.
How does LTE paging work between UE and eNodeB?
• UE sends RRC connection request message and eNodeB responds with RRC connection setup message. • If the LTE paging procedure is for PS data call, UE includes service request NAS message within RRC connection setup complete message.
Who is responsible for the initiation of LTE paging procedure?
As shown in the figure, MME is responsible for the initiation of LTE paging procedure. MME does this by forwarding S1AP paging message to one or more eNodeB. The contents and structure of S1AP paging message is mentioned below in the table-1. The LTE paging procedure is applicable to UE in ECM IDLE State.
What is paging in LTE?
How Paging Channel (PCH) is selected in LTE?
What is a paging message?
Paging procedure in 5G In a mobile network, when a device does not have any ongoing data transmissions, it enters an IDLE state in order to preserve battery. If new data arrives for the device, the network probes the IDLE device by sending a so-called "paging" message and the device correspondingly responds.
What is paging channel in LTE?
Paging Control Channel (PCCH) : This control channel is used for paging information when searching a unit on a network. Common Control Channel (CCCH) : This channel is used for random access information, e.g. for actions including setting up a connection.
What is default paging cycle in LTE?
Default Paging Cycle: This is known as “T” and it is the value after which the UE wakes up from idle mode to read the paging messages. Usually it is set to 1280 ms or 128 frames. This means that if a UE woke up in frame # 3 then it will wake up again in frame # 131 (after 128 frames) and then at frame # 259 and so on.
What is paging in UMTS?
IMSI paging procedure in UMTS: the paging request message is sent on a common radio channel and contains the identity of the paged mobile station (in this case the IMSI) in cleartext. The paging response message contains the mobile phone's temporary identity TMSI and is sent in clear on a dedicated channel.
Why do we need paging in LTE?
Paging in LTE network is used to inform and notify UE about various events. The propose of paging procedure is: To transmit paging information to a UE in RRC_IDLE state. To inform UEs in RRC_IDLE and UEs in RRC_CONNECTED state about a system information change.
What is paging in telecom?
In a mobile network, the paging operation is used to indicate the subscriber's position in order to establish a connection with another user, calling from a fixed or mobile environment.
What is RRC connection in LTE?
The RRC protocol is the signaling exchanged between the mobile and the evolved Node Base station (eNB) over the LTE-Uu radio interface. The RRC protocol performs the following functions: – Broadcast of system information related to the characteristics of the radio interface.
What is LTE handover?
Abstract: Handover in LTE occurs when a device moves from the cell coverage serving it towards another; a process where the user established session must not be interrupted due to this cell change.
What is measurement report in LTE?
Measurement Reports in 4G LTE are a way for a UE (“User Equipment”) or the mobile terminal to keep track of different signal strength measurements and report to the eNodeB if certain conditions are met. These conditions as reported as Measurement Reports assist the eNodeB in making handover decisions.
What is paging request in GSM?
IMSI paging procedure in GSM: the paging request message is sent on a common radio channel and contains the long-term identity of the paged mobile station IMSI in cleartext. The paging response message also contains the IMSI and is sent in clear on a dedicated channel.
What is paging in MSC?
Paging • Paging is the one-to-one communication between the mobile and the base station • Paging is a procedure the network uses to find out a subscriber's location before actual call establishment. • Paging is used to alert the mobile station of an incoming call.
What is paging DRX in 5g?
Paging is an important mechanism that helps with directing an incoming call to a UE when it is an Idle mode DRX (IDRX) to conserve energy. Network broadcasts the paging messages in the cells to convey an intimation about the incoming call to the UE in IDRX mode [9].
What is paging channel in CMC?
The Paging Channel is used to alert a mobile that there is a call or text message waiting. The alert is broadcast from all cells within a given area.
What is MIB and SIB in LTE?
In LTE there are several versions of System Information Blocks (SIB) and Master Information Block (MIB), each of them carries different information to UE. MIB message: is broadcasted on PBCH. There is only one type of MIB. SIB messages: are sent on PDSCH through RRC layer: •
What is channel sharing and borrowing?
Channels that are candidates for borrowing are available channels nominally assigned to one of the adjacent cells of the acceptor cell. If more than one adjacent cell has channels available for borrowing, a channel is borrowed from the cell with the greatest number of channels available for borrowing.
What is dedicated control channel?
Dedicated control channel (DCCH): A point-to-point bidirectional channel that transmits dedicated control information between a UE and the network. It is used by UEs that have RRC connection. The traffic channels are exclusively used for the transfer of user-plane information.
5G NR RRC Procedure: Paging - ProDeveloperTutorial.com
In this chapter we shall learn about RRC paging procedure. RRC paging function is used to trigger RRC Request and RRC Connection Resumption. When the UE in RRC-IDLE, UE will monitor paging channel for CN-initiated paging.
LTE Paging procedure
The LTE paging procedure is applicable to UE in ECM IDLE State. UE in this state are in RRC IDLE mode and do not have S1 connectivity with MME. The location of a UE in ECM IDLE state is known by MME on a per tracking area basis.
S1AP paging message in LTE
The table-1 below mentions S1AP paging message contents. UE identity index is used at eNodeB to calculate paging frame and is defined as follows: UE identity index = UE IMSI mod 1024
RRC LTE paging message
The table-2 below mentions RRC paging message contents. It is transferred using PCCH logical channel. PCH transport channel and PDSCH physical channel.
Paging Occasions in LTE
LTE UE in RRC IDLE mode use DRX to reduce the power consumption. DRX cycle will determine how frequently UE will check for paging messages. DRX cycle is broadcast within SIB2. It can have values of 32, 64, 128 or 256 radio frames. These corresponds to time intervals of 320, 640, 1280 and 2560ms.
LTE tutorial related links
This tutorial on LTE covers LTE basics and following sub topics on LTE: Main page features terminologies Frame TDD FDD Channel types PHY stack throughput VoLTE CA cell search network entry Timers PSS vs SSS Security LTE Bands EARFCN Hotspot router
What is paging in RRC?
There are a number of myths about paging. Let’s clear them all in one go. Paging is not only used to bring a UE from Idle to connected mode. It is also used in RRC Connected mode. It is used for the following use cases.
What Paging Occasion (PO) UE will wake up in each computed Paging Frame?
Continuing the example above. In order to find out which subframe UE will wake up in each subframe. Let’s compute i_s.
What is a UE in idle mode?
UEs in RRC Idle mode use Discontinuous Reception (DRX) also known as paging cycle to reduce power consumption. This DRX cycle determines how frequently UE check for paging messages. The default DRX cycle is broadcast within System Information Block 2 (SIB 2). The range for paging cycle varies as 32, 64, 128 and up to 256 radio frames.
Do UEs receive paging messages?
However, UEs are expected to check for paging messages at a similar rate to UEs in RRC Idle mode. This allows them to receive paging messages which trigger re-acquisition of the system information or trigger the reception of ETWS or CMAS information. These paging messages are not directed towards individual UE.
How does paging work in network?
In principle, the network could transmit the page the device over the entire coverage of the network, by broadcasting the paging message from every cell. However, that would obviously imply a very high overhead in terms of paging-message transmissions as the vast majority of the paging transmissions would take place in cells where the target device is not located. On the other hand, if the paging message is only to be transmitted in the cell in which the device is located, there is a need to track the device on a cell level. This would imply that the device would have to inform the network every time it moves out of the coverage of one cell and into the coverage of another cell. This would also lead to very high overhead, in this case in terms of the signaling needed to inform the network about the updated device location. For this reason, a compromise between these two extremes is typically used, where devices are only tracked on a cell-group level:
How does paging work?
Paging systems broadcast a short paging message simultaneously from many tall base stations or satellites transmitting at very high power (hundreds of watts to kilowatts). Systems with terrestrial transmitters are typically localized to a particular geographic area, such as a city or metropolitan region, while geosynchronous satellite transmitters provide national or international coverage. In both types of systems, no location management or routing functions are needed, since the paging message is broadcast over the entire coverage area. The high complexity and power of the paging transmitters allows low-complexity, low-power, pocket paging receivers with a long usage time from small and lightweight batteries. In addition, the high transmit power allows paging signals to easily penetrate building walls. Paging service also costs less than cellular service, both for the initial device and for the monthly usage charge, although this price advantage has declined considerably in recent years. The low cost, small and lightweight handsets, long battery life, and ability of paging devices to work almost anywhere indoors or outdoors are the main reasons for their appeal.
What is a service request in UE?
The Service Request message includes a special CS fallback indicator that informs the MME that the CS fallback is needed. This triggers the MME to activate the bearer context in the eNodeB with an indication to perform fallback to GERAN or UTRAN.
What is a paging identifier?
In legacy paging, IMSI and S-TMSI are used as a paging identifier, to indicate paged devices in a paging message. In early generations, IMSI was used for a paging identifier in order to restore the connection in case of lost or corruption of device context information (such as temporary identifier) in the CN. With native virtualization and cloud-based RAN support, only temporary identifier (5G-S-TMSI or I-RNTI) can be used as a paging identifier in 5G networks. If an attacker somehow obtains the device’s long-term identifier, in 5G network it still cannot attack the device because there is no long-term identifier-based paging to start with. Moreover, a new paging identifier I-RNTI is used as one-time paging identifier and must be refreshed after each paging.
What is the 5G standard?
The latest 5G standard includes privacy safeguards against IMSI catchers to ensure the privacy of paging message distribution. 5G exploits a privacy enhancement in uplink communication by using a concealed identifier SUCI (Subscription Concealed Identifier) instead of an IMSI analog called SUPI (Subscription Permanent Identifier). It is generated every time when a device wants to transmit data by using asymmetric cryptography. As for the downlink protection in 5G, paging protocols were enhanced by using new temporary identifiers 5G-S-TMSI and I-RNTI (to identify device context in a new RRC_INACTIVE state) instead of long-term IMSI and SAE Temporary Mobile Subscriber Identity (S-TMSI identifiers) [11].
What is paging message in RRC?
The paging message is used to inform UEs in RRC_IDLE and in RRC_CONNECTED about a system information change. If the UE receives a paging message indicating a system information modification, the UE by default expects that the system information will change at the next modification period boundary. Although the UE may be informed about changes in system information, no further details are provided, e.g., regarding which system information will change. The System Information Block Type 1 includes a value tag that indicates if a change has occurred in the SI messages. The UEs may use the tag on return from out-of-coverage to verify whether the previously stored SI messages are still valid. Furthermore, the UE considers stored system information to be invalid after three hours from the moment it was successfully confirmed as valid, unless otherwise specified.
What is the answer back capability of a paging device?
A paging handset with answer-back capability requires a modulator and transmitter with sufficient power to reach the distant base station. These requirements significantly increase the size and weight and reduce the usage time of the handheld pager. This is especially true for paging systems with satellite base stations, unless terrestrial relays are used.
What is paging in UE?
Paging is used to network initiated connection setup. Typically, paging procedure should allow UE to sleep with no receiver processing most of the time and briefly wakeup at predefined time interval to monitor paging information from the network.
Does MME forward paging?
5. MME will forward paging to multiple eNBs as UE can be registered with multiple tracking area. UE is addressed by S-TMSI.
Does ENB send paging to UE?
Then eNB will send a paging to UE as specified in TS 36.304
What is paging in LTE?
Paging in LTE network is used to inform and notify UE about various events. The propose of paging procedure is:
How Paging Channel (PCH) is selected in LTE?
System information block type 5 or 5bis (SIB 5 or SIB 5bis) defines all common channels used in idle mode. In one cell one or several PCH channels can be established.
