LTE Paging Parameter

Parameter Name	Parameter Description	Default Value
PagingId	The value component of the RDN.
maxNoOfPagingRecords	The maximum allowed number of paging records included in one Radio Resource Control (RRC) paging message. It is the allowed maximum number of UE that can be paged per paging occasion.	3
defaultPagingCycle	The paging cycle (also referred to as T) used by the RBS and broadcast in system information type 2. If the UE-specific Discontinuous Reception (DRX) cycle is provided in S1AP paging and has a smaller value than defaultPagingCycle, the UE-specific DRX cycle overrides defaultPagingCycle.	128
nB	Used to calculate the number and position of Paging Occasions (PO) and Paging Frames (PF). The numerical value of nB depends on the value of the defaultPagingCycle (T) and can be set to one of the following values: 4T, 2T, T, 1/2T,1/4T, 1/8T, 1/16T, 1/32T When nB is set to T, 2T or 4T, it determines the number of POs per PF, and the PO position in PF. When nB is set to a value smaller than T, it affects the System Frame Number of the PF, the position of PO in the PF, and also distribution of UE into groups with the same PF. When nB is set to a  smaller value, the groups are fewer but larger, or more but smaller.	T
pagingDiscardTimer	The length of time a received paging is retained or queued in the RBS before it is discarded. The timer should be set to the same (or smaller) value as the paging resend timer in MME (T3413). This setting  prevents the RBS from retaining or sending an old paging after the re-sent copy is received from the MME.	3

LTE Admission Control Parameter

Parameter Name	Parameter Description	Default Value
paArpOverride	Allocation Retention Priority level received from the Core Network that eNB interprets as the identifier for Privileged Access. The value zero will disable Privileged Access ARP override.	7
ulNonGbrRatio	This parameter sets the wanted uplink resource utilization ratio of Non-GBR bearers, e.g. for Mobile Broadband users, on transport network. The value given in this parameter specifies the Non-GBR part of the total bandwidth and the remaining part (1-ulNonGbrRatio) sets the GBR part of the total bandwidth. The parameter will be used by the Admission Control to balance GBR and Non-GBR use of resources.	500
dlNonGbrRatio	This parameter sets the wanted downlink resource utilization ratio of Non-GBR bearers, e.g. for Mobile Broadband users, on transport network. The value given in this parameter specifies the Non-GBR part of the total bandwidth and the remaining part (1-dlNonGbrRatio) sets the GBR part of the total bandwidth. The parameter will be used by the Admission Control to balance GBR and Non-GBR use of resources.	500
AdmissionControlId	The value component of the Relative Distinguished Name (RDN).
emergencyArpLimit	ARP (Allocation Retention Priority) value limit used for identifying ARP values that are considered to be part of the emergency (high priority) group. This limit value and all values below are considered to be of high priority. The value zero is introduced to turn off ARP handling.	7
nrOfBearersReserved	Number of bearers reserved for high priority group (bearers with low ARP values, Allocation Retention Priority values). Setting a high value for the reservation means low priority bearers will always be rejected.	0
nrOfRrcConnectedReserved	Number of RRC connections reserved for high priority UEs (handovers and where establishment cause is emergency). Setting a high value means non emergency UEs will always be rejected.	0
dlGbrAdmThresh	Admission threshold for load due to Guaranteed Bit Rate (GBR) bearers in the downlink, expressed as a fraction of the available resources.	1000
dlTransNwBandwidth	Downlink transport network bandwidth for LTE.	1000
ulGbrAdmThresh	Admission threshold for load due to Guaranteed Bit Rate (GBR) bearers in the uplink, expressed as a fraction of the available resources.	1000
ulTransNwBandwidth	Uplink transport network bandwidth for LTE.	1000

LTE Positioning Reference Signals (PRS)

Positioning reference signals are used for OTDOA User Plane Location Support. Positioning reference signals are transmitted with a periodicity Tprs[ms], as specified by prsPeriod. At each transmission occasion the position reference signals are sent in n,subf,con consecutive DL subframes. The number of consecutive DL subframes can be specified by nConsecutiveSubframes. In the figure below an example of the transmission scheme for PRS subframes is shown. 

To minimize the interference in the PRS subframes PDSCH is not scheduled in any RB in those subframes. Also note that PBCH, PSS and SSS all have higher priority than PRS. For a configuration with two antennas, PRS is transmitted from one antenna at the time. The same antenna is used the entire PRS occasion. For more information, refer to OTDOA User Plane Location Support. The more PRS subframes, the more accurate will the OTDOA positioning be. This comes at the expense of less resource available for PDSCH. The fraction of subframes used for PRS can be calculated by the following formula:

LTE - Cell-Specific Reference Signal (CRS)

To demodulate different downlink physical channels coherently, the UE requires complex valued channel estimates for each subcarrier. Known cell-specific reference symbols are inserted into the resource grid. The cell-specific reference signal is mapped to REs spread evenly in the resource grid, in an identical pattern in every RB.

When transmitting with several antennas, each antenna must transmit a unique reference signal. When one antenna transmits its reference signal, the other antenna must be silent. The mapping of the cell-specific reference signal on the resource grid therefore depends on the antenna configuration, see Figure. The pattern of cell-specific reference signals can be shifted in frequency compared to figure below. Which one of the six possible frequency shifts to use depends on the Physical Cell Identity (PCI) sent on Primary Synchronization Signal (PSS) and Secondary Synchronization Signal (SSS).

Holes are REs that must be silent because the cell-specific reference signal is transmitted on another antenna port. With one antenna port, the number of REs in one scheduling block occupied by the cell-specific reference signal and holes is 8. With two antenna ports the number is 16. The following table shows the total number of REs occupied by the cell-specific reference signal and holes, for the bandwidths available:

LTE - Resource Structure

Time Domain Structure

In the time domain, the signal is structured in the following parts:

Time Domain Signal Structure

Structure Element	Description
Radio Frames	10 ms length
Subframes	1 ms length. One frame consists of 10 subframes.
Slot	0.5 ms length. One subframe consists of two slots.
OFDM symbol	Approximately 71.4 μs length. One slot consists of 7 OFDM symbols.

  

Frequency Domain Structure

Orthogonal Frequency-Division Multiplexing (OFDM) utilize a large number of subcarriers. Each subcarrier is orthogonal to all other subcarriers. Subcarrier spacing is equal to the subcarrier bandwidth, which is 15 kHz, see Figure

Resource Element

The smallest resource unit handled in LTE consists of the combination of:

• The smallest time domain unit, one OFDM symbol

• The smallest frequency domain unit, one subcarrier

This unit is called Resource Element (RE). An RE that is not used for transmission is referred to as a hole

Resource Block

A number of REs are grouped into a physical Resource Block (RB). An RB is defined as follows:

• In the time domain: 7 OFDM symbol times (one slot)

• In the frequency domain: 12 consecutive subcarriers

Scheduling Block

A scheduling block consists of two RBs adjacent in time and with the same subcarriers. A scheduling block is the smallest unit that can be scheduled to user equipment.

LTE - Resource Block Flexible Bandwidth

A transmitted OFDMA signal can be carried by a number of parallel subcarriers. Each LTE subcarrier is 15 kHz. Twelve subcarriers (180 kHz) are grouped into a resource block. The downlink has an unused central subcarrier. Depending on the total deployed bandwidth, LTE supports a varying number of resource blocks.

The following illustration shows resource block definition:

A resource block is limited in both the frequency and time domains. One resource block is 12 subcarriers during one slot (0.5 ms).

In the downlink, the time-frequency plane of OFDMA structure is used to its full potential. The scheduler can allocate resource blocks anywhere, even non-contiguously.

 A variant of OFDMA is used in the uplink. This variant requires the scheduled bandwidth to be contiguous, forming in effect a single carrier. The method, called SC-FDMA, can be considered a separate multiple access method.

A user is scheduled every Transmission Time Interval (TTI) of 1 ms, indicating a minimum of two consecutive resource blocks in time at every scheduling instance. The minimum scheduling in the frequency dimension is 12 subcarriers that is the width of one resource block in the frequency dimension. The scheduler is free to schedule users both in the frequency and time domain. Show in Figure as example of two users scheduled in the time and frequency domain for the downlink and the uplink:

The defined LTE bandwidths in 3GPP are the following:

In Table  Bandwidths and Resource Blocks Specified in 3GPP

Bandwidth	Number of Resource Blocks nRB
1.4 MHz	6
3.0 MHz	15
5.0 MHz	25
10.0 MHz	50
15.0 MHz	75
20.0 MHz	100

LTE - User Equipment

Five UE categories have been specified by 3GPP in User Equipment (UE) radio access capabilities, 3GPP TS 36.306. Each category is specified by a number of downlink and uplink physical layer parameter values listed in fig. 

 3GPP has in User Equipment (UE) radio transmission and reception, 3GPP TS 36.101 specified one power class, UE power class 3, that has a maximum output power of 23 dBm.