1. 助理教授：吳俊興 助教：吳振宇 國立高雄大學 資訊工程學系
教育部行動寬頻尖端技術人才培育計畫-小細胞基站聯盟中心
示範課程：行動與無線區網整合
Week #16 LAA與LSA
助理教授：吳俊興
助教：吳振宇
國立高雄大學 資訊工程學系

2. Outline Introduction LTE-U and LAA Regulatory Requirements
Spectrum Considerations
LAA Carrier Aggregation Feasibility Study
Deployment scenarios for LAA
Coexistence
Design targets, functionalities and solutions for LAA

3. Introduction
LTE-U (LTE-Unlicensed), or as it is also known LTE-LAA (LTE-License Assisted Access) utilizes unlicensed spectrum, typically in the 5GHz band to provide additional radio spectrum
First introduced in Rel13
Built upon carrier aggregation capability of LTE-A
No changes are needed to the core network

4. 3GPP LTE-U and LTE-LAA
To evaluate LTE enhancements for a single global solution framework for licensed-assisted access (LAA) to unlicensed spectrum
Approved at 3GPP TSG RAN #65
Complementary access using the unlicensed band would be supported by licensed operation, the quality of which can never be matched by unlicensed operation

5. Three Ways of Deployment
Downlink only
Uplink and downlink
FDD / TDD aggregation
The use of carrier aggregation mixes between FDD and TDD

6. LTE-unlicensed Operation Modes

7. LTE-advanced Aggregation Between FDD and TDD Bands

8. Licensed-Assisted Access (LAA)
LTE in unlicensed spectrum serves as an additional tool to maximize the value for users, while the core of the activity remains anchored to the licensed spectrum
The primary component carrier in licensed spectrum will still be used to carry some (or all) of the control signal (and possibly also data, e.g. retransmissions) of the traffic carried over the carrier in unlicensed spectrum
Unlicensed spectrum is better used as “Licensed-Assisted Access”, considered as a secondary component carrier in a carrier aggregation scenario
The use of unlicensed spectrum also increases the need for more licensed spectrum

9. LAA Spectrum
Define 5 GHz unlicensed LAA band or bands within frequency limits 5150 – 5925 MHz
The PHY layer options considered for LAA have at least the following characteristics
Support for at least 20 MHz system BW option in the 5 GHz band
System bandwidths < 5 MHz are not considered for PHY layer options in LAA
Potential interference sources
IEEE (a, n, ac)
Weather radar

10. 3GPP TR36.889 (R13): Study on Licensed-Assisted Access to Unlicensed Spectrum
Scope
References
Definitions, symbols and abbreviations
Regulatory requirements
Spectrum considerations and LAA carrier aggregation feasibility study
Deployment scenarios for LAA
Design targets, functionalities and solutions for LAA
Coexistence evaluations
Conclusions
Annex A: Evaluation methodology
Annex B: Evaluation results for co-channel coexistence
Annex C: Change history
( )

11. Unlicensed Spectrum Availability in Different Regions LTE

12. Spectrum Considerations in Europe
5 GHz spectrum allocations in Europe
Summary of existing and proposed EU regulations for WAS/RLANs in the 5GHz band

13. Transmit Power and Emission Requirement in Europe

14. DFS Requirements in Europe

15. LBT Requirements in Europe
Parameter
Requirement
Comment
Clear Channel Assessment (CCA) time
Minimum 20μs
Channel Occupancy time
Minimum 1 ms, maximum10 ms
Idle period
Minimum 5% of channel occupancy time
Fixed frame period
Equals to Channel Occupancy time + Idle Period
Short control signaling transmission time
Maximum duty cycle of 5% within an observation period of 50ms
Part of Channel occupancy time
CCA Energy detection threshold
Assuming receive antenna gain G=0dBi:
If EIRP=23dBm at transmitter
Threshold ≤ -73 dBm/MHz
Otherwise (different transmit power levels, PH)
Threshold = -73(dBm/MHz) + 23(dBm) – PH(dBm)
For WAS/RLAN
LBT requirements for Frame-Based-Equipment in Europe
Parameter
Requirement
Comment
Clear Channel Assessment (CCA) time
Minimum 20μs
Also referred to as CCA time slot
N (number of clear idle slots) in extended CCA
N shall be randomly selected in the range 1..q every time, q=4…32
Channel Occupancy time
<= (13/32) × q ms
Idle period
At least the duration of a random factor N multiplied by the CCA time slot.
Short control signaling transmission time
Maximum duty cycle of 5% within an observation period of 50ms
Part of Channel occupancy time
CCA Energy detection threshold
Assuming receive antenna gain G=0dBi:
If EIRP=23dBm at transmitter
Threshold ≤ -73 dBm/MHz
Otherwise (different transmit power levels, PH)
Threshold = -73(dBm/MHz) + 23(dBm) – PH(dBm)
For WAS/RLAN
LBT requirements for Load-Based-Equipment in Europe

16. Spectrum Considerations in Taiwan
In Taiwan the bands MHz, MHz, MHz and MHz are allocated to RLANs
Table and Table summarize the current regulatory requirements for transmit power and DFS in Taiwan [40]. DFS is mandate for MHz
Recently, work for specifying requirements for allowing RLANs in MHz and MHz has started but the detailed regulatory requirements for this has not yet been specified
Additionally specification work for allowing MHz outdoor has started, this assumes that DFS will be performed, but detailed requirements are not yet defined

17. Transmit power requirements for 5GHz band in Taiwan
Frequency Range (GHz) *
and
*For indoor use only
Peak transmit power < min(a, b) (dBm) A 17 24 30 B
4+10logB
11+10logB
17+10logB
B is the 26-dB emission bandwidth in MHz
Peak PSD (dBm/MHz) 4 11
Resolution bandwidth 1 MHz
Assumed Antenna Gain (dBi) 6
6**
Peak power is reduced by G-6 dB for directional antennas with gain > 6 dBi;
** Fixed point to point operation power scaling threshold is 23 dBi
Out of band emission
Frequency Support (GHz)
Outside 5.25 – 5.35
Outside
Outside
EIRP (dBm/MHz)
-27
-17
Transmit Power Control
N/A
TPC to 6 dB below a mean EIRP of 30 dBm. No TPC for mean EIRP < 27 dBm
DFS
Required

18. DFS requirements for 5.470-5.725GHz band in Taiwan

19. Licensed Spectrum Needs for LAA
Unlicensed spectrum is better used as “Licensed-Assisted Access” integrated into LTE
Unlicensed spectrum can never replace the need for more licensed spectrum
Inability to be used in macro cells providing wide-area coverage and
Inability to provide highly robust quality-of-service due to the uncontrolled interference
The use of LTE in unlicensed spectrum can serve as a useful additional tool by operators
The primary component carrier in licensed spectrum will be used to carry some (or all) of the control signal (and possibly also data, e.g. retransmissions) of the traffic carried over the carrier in unlicensed spectrum
The use of unlicensed spectrum also increases the need for more licensed spectrum
Carrier aggregation between a macro cell operating in licensed spectrum and clusters of many small cells (remote radio heads) operating only in large chunks of unlicensed spectrum

20. LAA Carrier Aggregation Feasibility Study
Feasibility of UE operation
Feasibility of BS operation
Band definition for unlicensed operation of LTE in 5GHz spectrum
Band range
Suitable duplex method for unlicensed bands
UE RF devices for 5GHz band

21. Feasibility of UE Operation
For 5GHz spectrum available for WAS/RLAN, regulatory requirements such as allowed transmit output power or TPC requirements need to be taken into account
It is reasonable to assume one single front end filter in UE implementation to cover the entire 5GHz spectrum
This does not preclude consideration of other implementation options in the WI phase
For aggregating carrier in unlicensed 5GHz band for inter-band CA, there exists some UE RF architecture that could be feasible
It is feasible for UEs to operate in the 5GHz unlicensed spectrum
RF requirements should be specified taking into account issues including implementation complexity and performance

22. Feasibility of BS Operation
While BS implementation considerations may be different from those of UE in terms of performance, implementation complexity, and fair access to the unlicensed carriers in the presence of WiFi, there are no major issues reported during the study
It is noted that to enable fair access between LAA BS and WiFi AP/STAs, some LAA BS RF requirements may require further study
In summary, it is feasible for BSs to operate in 5GHz unlicensed spectrum. RF requirements should be specified taking into account issues including implementation complexity and performance

23. Band Definition for Unlicensed Operation of LTE in 5GHz Spectrum
Band range
Define 5 GHz unlicensed LAA band or bands within frequency limits 5150 – 5925 MHz
Suitable duplex method for unlicensed bands
In case of eNB operating DL+UL LAA over the same carrier in unlicensed spectrum, the DL transmission burst(s) and UL transmission burst(s) on LAA can be scheduled in a TDM manner while any instant in time can be part of a DL transmission burst or an UL transmission burst, which is different from existing Frame Structure type 2 (FS2)
Potential duplex methods for LAA operation may consider both DL-only and/or DL+UL transmission
Since the duplex method is tied to frame structure, the duplex method for 5GHz unlicensed band shall be based on the physical layer design on L1 enhancements for LAA
UE RF devices for 5GHz band
It is recommended that radio requirements should be specified such that a single filter implementation for UE across the entire frequency range from 5150 to 5925 MHz is possible

24. LTE in 5 GHz Unlicensed Bands and CA
With increased demand for wireless access
3GPP is becoming interested in the 5GHz National Information Infrastructure (UNII)
bands from GHz, which are mainly used by Wi-Fi networks presently
The wider spectrum in 5 GHz can be utilized by LTE operators to enhance their service in licensed bands

25. LTE-U Common Deployment Scenarios

26. Scenario 1 The licensed small cells (F2) do not exist
Carrier aggregation is implemented with
Licensed macro cell (F1)
Unlicensed small cells (F3)
An ideal backhaul
Can be non-colocated
This scenario uses one macro
The mobility management and improving coverage
Indoor and outdoor environments
(e.g., optical fiber with low latency and high throughput)
保證The mobility management and improving coverage

27. Scenario 2 The licensed macro cell (F1) does not exist
Carrier aggregation without macro cell coverage is implemented with
Licensed small cell (F2)
Unlicensed small cell (F3)
an ideal backhaul and co-location
Proper for indoor services

28. Scenario 3
Both the licensed macro cell and small cell use the same carrier (F1)
Carrier aggregation is implemented with
Licensed small cell (F1)
Unlicensed small cell (F3)
An ideal backhaul and co-location
F1 and F3
Can be connected with an ideal backhaul or a non-ideal backhaul
Both indoor and outdoor environments
(non-ideal) backhaul；即基站間不一定會以光纖相連。

29. Scenario 4
The licensed macro cell and licensed small cell use different carriers (F1) and (F2)
Carrier aggregation is implemented with
Licensed small cell (F2)
Unlicensed small cell (F3)
An ideal backhaul and co-location
F1 and F2
Can be connected with an ideal backhaul or a non-ideal backhaul
Both indoor and outdoor environments

30. LAA Deployment Scenarios (R13 TR36.889)
Scenario 1: CA between licensed macro cell (F1) and unlicensed small cell (F3)
Scenario 2: CA between licensed small cell (F2) and unlicensed small cell (F3) without macro cell coverage
Scenario 3: Licensed macro cell and small cell (F1), with CA between licensed small cell (F1) and unlicensed small cell (F3)
Scenario 4: F1 + F2 + F3 - CA between licensed SC (F2) and unlicensed SC (F3)
- CA between macro cell (F1), licensed SC (F2) and unlicensed SC (F3) if ideal backhaul between macro and small cells

31. Coexistence Scenarios
The coexistence between Wi-Fi and LTE-U
The coexistence between LTE-Us of different operators

32. Case 1: LTE-U vs. Wi-Fi LTE-U and Wi-Fi
use different MAC/PHY designs
are usually operated by different operators
LBT-regulated or LBT-non-regulated
avoid mutual interference if both systems use the same unlicensed carrier
A fair Time Division Multiplexing (TDM) scheme
Leveraged to avoid the interference between LTE-U and Wi-Fi if they use the same unlicensed spectrum
Listen before talk
Because
there are great differences between these
two systems, such as different radio frame
structure and transmission scheduling
(see Section “LTE vs. Wi-Fi”), the
implementation leads to high complexity

33. Case 2: LTE-U vs. LTE-U
LTE-Us from different operators coexist in the same 5 GHz unlicensed spectrum
LBT : reduce the interference and improve the spectrum efficiency
multiple LTE-U nodes simultaneously identify a clear unlicensed spectrum
online auction mechanism

34. Comparison of LTE and Wi-Fi
Comparison between LTE and Wi-Fi in the PHY/MAC layers

35. Design Targets of an LAA System
A single global solution framework allowing compliance with any regional regulatory requirements
A single global solution framework for LAA should be defined to ensure that LAA can be operated according to any regional regulatory requirements
Furthermore, LAA design should provide sufficient configurability to enable efficient operation in different geographical regions
Effective and fair coexistence with Wi-Fi
The LAA design should target fair coexistence with existing Wi-Fi networks to not impact Wi-Fi services more than an additional Wi-Fi network on the same carrier, with respect to throughput and latency
Effective and fair coexistence among LAA networks deployed by different operators
The LAA design should target fair coexistence among LAA networks deployed by different operators so that the LAA networks can achieve comparable performance, with respect to throughput and latency

36. Functionalities Required for an LAA System
Listen-Before-Talk (LBT)
Applying a clear channel assessment (CCA) check before using the channel
Energy detection (at least 20 us) to determine presence or absence of other signals
Discontinuous transmission on a carrier with limited maximum transmission duration
4ms in Japan
Dynamic frequency selection (DFS) for radar avoidance in certain bands/regions
Carrier selection for low interference and good co-existence
Transmit Power Control
Able to reduce the transmit power in a proportion of 3dB or 6dB
RRM measurements including cell identification
Enabling mobility between SCells and robust operation in the unlicensed band
Automatic Gain Control (AGC) setting
Coarse synchronization
Fine frequency/time estimation at least for demodulation
Channel-State Information (CSI) measurement, including channel and interference

37. Listen-Before-Talk (Clear Channel Assessment)
The listen-before-talk (LBT) procedure is defined as a mechanism by which an equipment applies a clear channel assessment (CCA) check before using the channel
The CCA utilizes at least energy detection to determine the presence or absence of other signals on a channel in order to determine if a channel is occupied or clear, respectively
European and Japanese regulations mandate the usage of LBT in the unlicensed bands
Apart from regulatory requirements, carrier sensing via LBT is one way for fair sharing of the unlicensed spectrum and hence it is considered to be a vital feature for fair and friendly operation in the unlicensed spectrum in a single global solution framework

38. PHY Layer Options for LAA
The PHY layer options considered for LAA have at least the following characteristics
Support for at least 20MHz system BW option in the 5GHz band
System bandwidths < 5 MHz are not considered for PHY layer options in LAA

39. Solutions for Operation in Unlicensed Spectrum
Physical layer aspects
Discontinuous transmission on the downlink
RRM measurements and reporting
CSI measurements and reporting
Downlink transmissions
Scheduling and HARQ
Listen-Before-Talk Design
UL transmission
Transmission burst
Higher layer aspects
Random Access (RA)
HARQ operation
DRX
QoS control
RRM measurement and reporting
PCI confusion and PCI collision
In-device coexistence (IDC)
Listen-Before-Talk (LBT)

40. LTE-unlicensed Environment

41. Load-based and Frame-based Operation Principles

42. Short Control Signalling Principle

43. LTE Capacity Compared to the Wi-Fi Capacity in the Office Environment Networks.

44. Example Environment Used in the Simulations

45. Outdoor Small Cell Range at 5 GHz Band

46. Performance per Access Node with Two LTE or Two Wi-Fi Networks on the Same Channel

47. Coexistence Performance Between LTE and Wi-Fi

48. Example Measurement for Lower Part of 5 GHz Band

49. Example Measurement over the Full 5 GHz Band in Europe

50. Example Network Utilization at Lower Part of 5 GHz Band

51. Uplink Link Budget Comparison

52. Downlink Link Budget Comparison

53. LSA Concept Describe the interface between the NM and LC
A system architecture for operation of mobile broadband services in the MHz MHz band under Licensed Shared Access (LSA)
ETSI TS "Reconfigurable Radio Systems (RRS); system architecture and high level procedures for operation of Licensed Shared Access (LSA) in the 2300 MHz-2400 MHz band"
ETSI TS "Reconfigurable Radio Systems (RRS); Information elements and protocols for the interface between LSA Controller (LC) and LSA Repository (LR) for operation of Licensed Shared Access (LSA) in the MHz MHz band"
ETSI TS "Reconfigurable Radio Systems (RRS); System requirements for operation of Mobile Broadband Systems in the MHz MHz band under Licensed Shared Access (LSA)"
ETSI TR "Electromagnetic compatibility and Radio spectrum Matters (ERM); System Reference document (SRdoc); Mobile broadband services in the MHz MHz frequency band under Licensed Shared Access regime"
Aimed at enabling access for mobile/fixed communication networks (MFCNs) in those CEPT countries
Where access to the band is foreseen but cannot be provided without restrictions due to incumbent usage
Describe the interface between the NM and LC

54. LSA Architecture The LC is a kind of NMLS (see TS 32.101 [2])
The interface between the NM and LC is a Type 7 interface

55. LSA Functionality
Two deployment scenarios are considered and different functionality is specified for the interface between the LC and NM
Deployment scenario 1
In this scenario the LC is a relay for the LSRAI received from the LR
The LC forwards it to the NM
Deployment scenario 2
In this scenario the LSRAI is not forwarded to the NM
The LC computes radio configuration constraints based on the LSRAI received from the LR and radio planning parameters received from the NM
These radio configuration constraints are sent to the NM

56. LSA Business Level Requirements
The LSA licensee shall be able to use LSA spectrum resources
Requirements for scenario 1
Requirements for scenario 2

57. High-level Use Cases for Scenario 1 (LSA Spectrum Resources Usage)
Use case stage
Evolution/Specification
Goal
The goal is to enable usage of LSA spectrum resources by the LSA licensee
Actors and Roles
MFCN, NM, LC, LR
Telecom resources
Assumptions
Connectivity between NM and LC
Connectivity between LR and LC
Pre-conditions
LSA spectrum resources are available. The LR, LC and MFCN are set up and running
Begins when
The LC registers with the LR
Step 1 (M)
The LC receives LSRAI from the LR and forwards this information to the NM
Step 2 (M)
The NM informs the LC that necessary configuration changes in the MFCN have been applied. The LC forwards this information to the LR
Step 3 (M)
The LC receives LSRAI updates and forwards these to the NM. When the necessary configuration changes have been applied in the MFCN the LC is notified. The LC forwards this information to the LR.
Ends when
The LC deregisters from the LR, and forwards this information to the NM
Exceptions
Post-conditions
The LC is deregistered from the LR, and LSA spectrum resources cannot be used any more by the LSA licensee
Traceability
REQ-LC-IRP-CON-001

58. High-level Use Cases for Scenario 2 (LSA Spectrum Resources Usage)
Use case stage
Evolution/Specification
Goal
The mobile network uses LSA spectrum resources within the constraints provided by the LC
Actors and Roles
The LC providing constraints on parameters of cells operating on LSA frequencies to the NM
The NM providing ranges for cells parameters to the LC
Telecom resources
NM, LC
Assumptions
Connectivity between NM and LC is established
Connectivity between LR and LC is established
Preconditions
LSA spectrum resources are available.
The LR, LC and MFCN are set up and running
Begins when
The LC receives information on LSA spectrum resource usage by incumbents from the LR
Step 1 (M)
The LC requests to the NM the cell parameters range suitable for the mobile network
Step 2 (M)
The LC determines the constraints on the mobile network that need to be fulfilled taking into account the ranges provided by the NM
Step 3 (M)
The LC provides the NM with the constraints on the mobile network
Step 4 (M)
The NM applies the constraints and confirms to the LC when constraints are fulfilled
Ends when
The LC has received a confirmation from the mobile network that the constraints are fulfilled
Traceability
REQ-LC-IRP-CON-001

59. Requirements for Scenario 1
REQ-LC-IRP-SC1-FUN
Requirements
001
The LC shall support a capability allowing the NM to trigger the registration of the LC with the LR
002
The LC shall support a capability allowing to inform the NM about completion of the registration with the LR
003
The LC shall support a capability allowing the NM to trigger the de-registration of the LC with the LR
004
The LC shall support a capability allowing to inform the NM about completion of the de-registration with the LR
005
The LC shall support a capability allowing the NM to read the LSRAI that the LC has received from the LR
006
The LC shall support a capability allowing to inform the NM about changes of the LSRAI that the LC has received from the LR
007
The NM shall support a capability allowing to inform the LC that configuration changes in the MFCN (if needed) have been applied according to previously received LSRAI
008
The NM shall support a capability allowing LC to read if configuration changes in the MFCN (if needed) have been applied according to previously received LSRAI

60. Requirements for Scenario 2
REQ-LC-IRP-SC2-FUN
Requirements
001
The LC shall support a capability allowing the NM to trigger the registration of the LC with the LR
002
The LC shall support a capability allowing to inform the NM about completion of the registration with the LR
003
The LC shall support a capability allowing the NM to trigger the de-registration of the LC with the LR
004
The LC shall support a capability allowing to inform the NM about completion of the de-registration with the LR
005
The LC shall support a capability allowing the NM to obtain the constraints on cells parameters that need to be satisfied in order to use LSA spectrum resources
006
The NM shall support a capability allowing the LC to obtain ranges of acceptable parameters for the cells operating on LSA frequencies
007
The LC shall take into account LSRAI in the LSA cells constraints calculation
008
The LC shall take into account the range for cell parameters provided by NM in the LSA cells constraints calculation

61. Use Cases for Scenario 1 (Trigger LC Registration)
Use case stage
Evolution/Specification
Goal
The goal is to trigger by the NM the registration of the LC with the LR
Actors and Roles
NM, LC
Telecom resources
Assumptions
Connectivity between NM and LC
Connectivity between LR and LC
The actor triggering the LC registration is located at the NM
Pre-conditions
LSA spectrum resources are available. The LR, LC, NM and MFCN are set up and running
Begins when
The LSA licensee decides to use LSA spectrum resources
Step 1 (M)
The NM triggers the LC to register with the LR
Step 2 (M)
The LC registers with the LR according to the registration procedure
Step 3 (M)
The LC notifies the NM about the completion of the registration procedure with the LR
Ends when
The NM has received the information on the completion of the registration procedure
Exceptions
Connectivity between NM and LC, or LR and LC is lost
Post-conditions
The LSA licensee can use LSA spectrum resources
Traceability
REQ-LC-IRP-SC1-FUN-001

62. Use Cases for Scenario 1 (LC Registration)
Use case stage
Evolution/Specification
Goal
The goal is to register the LC with the LR, and to inform the NM about this
Actors and Roles
NM, LC
Telecom resources
Assumptions
Connectivity between NM and LC
Connectivity between LR and LC
The actor triggering the LC registration is located at the LC
Pre-conditions
LSA spectrum resources are available. The LR, LC, NM and MFCN are set up and running
Begins when
The LSA licensee decides to use LSA spectrum resources
Step 1 (M)
The LC registers with the LR according to the registration procedure
Step 2 (M)
The LC notifies the NM about the completion of the registration procedure with the LR
Ends when
The NM has received the information on the completion of the registration procedure
Exceptions
Connectivity between NM and LC, or LR and LC is lost
Post-conditions
The LSA licensee can use LSA spectrum resources
Traceability
REQ-LC-IRP-SC1-FUN-002

63. Use Cases for Scenario 1 (Trigger LC De-registration)
Use case stage
Evolution/Specification
Goal
The goal is to de-register the LC with the LR, and to inform the NM about this
Actors and Roles
NM, LC
Telecom resources
Assumptions
Connectivity between NM and LC
Connectivity between LR and LC
The actor triggering the LC de-registration is located at the NM
Pre-conditions
The LR, LC, NM and MFCN are set up and running. The LC has registered with the LR. The LSA licensee is using LSA spectrum resources
Begins when
The LSA licensee decides to not use LSA spectrum resources any more, and stops using them
Step 1 (M)
The NM triggers the LC to de-register with the LR
Step 2 (M)
The LC de-registers with the LR according to the de-registration procedure
Step 3 (M)
The LC notifies the NM about the completion of the de-registration procedure with the LR
Ends when
The NM has received the information on the completion of the de-registration procedure
Exceptions
Connectivity between NM and LC, or LR and LC is lost
Post-conditions
The LSA licensee cannot use LSA spectrum resources any more
Traceability
REQ-LC-IRP-SC1-FUN-003

64. Use Cases for Scenario 1 (LSRAI Request)
Use case stage
Evolution/Specification
Goal
The goal is to allow the NM to trigger synchronisation of the LSRAI in the NM with the LSRAI in the LR
Actors and Roles
NM, LC
Telecom resources
Assumptions
Connectivity between NM and LC
Connectivity between LR and LC
Pre-conditions
The LR, LC, NM and MFCN are set up and running. The LC has registered with the LR. The LSA licensee wants to start using LSA spectrum resources or is already using it
Begins when
The LSA licensee wants to synchronise the LSRAI in the NM with the LSRAI in the LC received from the LR
Step 1 (M)
The NM sends a LSRAI request message to the LC
Step 2 (M)
The LC processes this request and forwards it to the LR according to the LSRAI request procedure
Step 3 (M)
The LR sends the LSRAI response message to the LC according to the LSRAI request procedure
Step 4 (M)
The LC processes the LSRAI response message and forwards it to the NM
Ends when
The NM has received the updated LSRAI
Exceptions
Connectivity between NM and LC, or LR and LC is lost
Post-conditions
The LSA licensee can use updated LSRAI
Traceability
REQ-LC-IRP-SC1-FUN-005

65. Use Cases for Scenario 1 (LSRAI Notification)
Use case stage
Evolution/Specification
Goal
The goal is to allow the LR to trigger synchronisation of the LSRAI in the NM with the LSRAI in the LR
Actors and Roles
NM, LC
Telecom resources
Assumptions
Connectivity between NM and LC
Connectivity between LR and LC
Pre-conditions
The LR, LC, NM and MFCN are set up and running. The LC has registered with the LR. The LSA licensee wants to start using LSA spectrum resources or is already using it
Begins when
The LR wants to synchronise the LSRAI in the LC (and NM) with the LSRAI in the LR
Step 1 (M)
The LR sends a LSRAI notification to the LC according to the LSRAI notification procedure
Step 2 (M)
The LC processes the notification and forwards it to the NM
Step 3 (M)
The NM acknowledges reception of the notification to the LC
Step 4 (M)
An LSRAI notification ack is sent back to the LR according to the LSRAI notification procedure
Ends when
The LR has received the LSRAI notification ack
Exceptions
Connectivity between NM and LC, or LR and LC is lost
Post-conditions
The LSA licensee can use updated LSRAI
Traceability
REQ-LC-IRP-SC1-FUN-006

66. Use Cases for Scenario 2 (LC Initialization)
Use case stage
Evolution/Specification
Goal
The mobile network can start using LSA spectrum resources
Actors and Roles
The function in the NM providing ranges for the parameters of cells operating on LSA frequencies to the LC
The function in the LC providing constraints on parameters of cells operating on LSA frequencies to the NM, taking into account the related ranges provided by NM and the LSRAI provided by LR
Telecom resources
NM, LC
Assumptions
Connectivity between NM and LC is established
Connectivity between LR and LC is established
The LC has the functionality to convert LSRAI and parameters ranges provided by NM to constraints on some parameters of cells operating on LSA frequencies and to inform the NM about changes on those constraints
Pre-conditions
The LR, LC, NM and MFCN are set up and running
The NM has access to the list of cells operating on LSA frequencies
Begins when
The LC has received up-to-date information on current LSA spectrum resource usage by LSA incumbent from the LR
Step 1 (M)
The LC asks to the NM the list of geographical areas containing the cells operating on LSA frequencies to the LC, as well as related ranges for cells parameters
Step 2 (M)
The LC computes, for each geographical area provided by NM, the constraints on parameters, taking into the LSRAI provided by LR in order to satisfy current LSA spectrum resource usage by incumbents and also taking into account the ranges on parameters provided by NM in order to satisfy the LSA Licensee requirements
Note: The LSA Licensee requirements are useful in order to find a suitable solution (LSA cell configuration parameters) by LC to minimize the probability of LSA cell switch off event (in the case in which the new LSA cell configuration parameters, calculated by LC, introduce a coverage or capacity or QoS degradation in the whole LSA licensee network).
Step 3 (M)
The LC provides the NM with the constraints on cells parameters for cells operating on LSA frequencies
Step 4 (M)
The NM applies the necessary configuration changes
Step 5 (M)
The NM confirms to the LC that the necessary configuration changes have been applied or not
Ends when
Ends when all steps identified above are completed or when an exception occurs
Exceptions
LC loses connectivity with the LR
Post-conditions
The NM is able to properly configure and activate cells operating on LSA frequencies, using the constraints on cells parameters provided by the LC
Traceability
REQ-LC-IRP-SC2-FUN-005, REQ-LC-IRP-SC2-FUN-006, REQ-LC-IRP-SC2-FUN-007, REQ-LC-IRP-SC2-FUN-008

67. Use Cases for Scenario 2 (LSA Spectrum Resource Availability Change)
Use case stage
Evolution/Specification
Goal
The mobile network operates according to the changed LSRAI given to the LC from the LR and according to the ranges for cell parameters given to the LC from the NM
Actors and Roles
The function in the NM providing parameters ranges for the parameters of cells operating on LSA frequencies to the LC
The function in the LC providing constraints on parameters of cells operating on LSA frequencies to the NM, taking into account the related ranges provided by NM and the LSRAI provided by LR
Telecom resources
NM, LC
Assumptions
Connectivity between NM and LC is established
Connectivity between LR and LC is established
The LC has the functionality to convert LSRAI and parameters ranges provided by NM to constraints on some parameters of cells operating on LSA frequencies and to inform the NM about changes on those constraints
Pre-conditions
The LR, LC, NM and MFCN are set up and running
The LC has the knowledge of which cells are operating on LSA frequency and what constraints are applied in the network
Cells are working according to previously provided constraints from the LC via the NM
Begins when
The LC has received up-to-date information on current LSA spectrum resource usage by incumbents from the LR
Step 1 (M)
The LC determines, also taking into account the validity ranges for cell parameters provided by NM, if the constraints on cells parameters need to be updated in order to satisfy the changes in LSA spectrum resources availability
Step 2 (M)
If required, the LC provides the NM with the new constraints on parameters, for each cell impacted by the changes in LSA spectrum resources availability
Step 3 (M)
The NM configures the impacted cells according to the new constraints
Step 4 (M)
The NM confirms to the LC that the necessary configuration changes have been applied
Ends when
The LC has received a confirmation from the NM that the necessary configuration changes have been applied
Exception
The LC loses connectivity with the LR
The configuration of the affected cells is not successful
Post-conditions
The affected cells are working according to the new constraints
Traceability
REQ-LC-IRP-SC2-FUN-005, REQ-LC-IRP-SC2-FUN-007, REQ-LC-IRP-SC2-FUN-008

68. Use Cases for Scenario 2 (Network Deployment Update)
Use case stage
Evolution/Specification
Goal
The mobile network can start using LSA spectrum resources according to the new constraints on parameters, following a change in network deployment
Actors and Roles
The function in the NM providing ranges for the parameters of cells operating on LSA frequencies to the LC
The function in the LC providing constraints on parameters of cells operating on LSA frequencies to the NM, taking into account the related ranges provided by NM and the LSRAI provided by LR
Telecom resources
NM, LC
Assumptions
Connectivity between NM and LC is established
Connectivity between LR and LC is established
The LC has the functionality to convert LSRAI and parameters ranges provided by NM to constraints on some parameters of cells operating on LSA frequencies and to inform the NM about changes on those constraints
Pre-conditions
The LR, LC, NM and MFCN are set up and running
The NM has access to the list of cells operating on LSA frequencies
The LC has received up-to-date information on current LSA spectrum resource usage by incumbents from the LR
Begins when
The NM detects a change in the deployment of cells operating on LSA frequencies (e.g., a cell has been added to the network, removed from the network or updated)
Editor's note: it is FFS whether details need to be described on how the NM detects a change in the deployment of cells operating on LSA frequencies
Step 1 (M)
The NM provides the LC with the geographical areas related to the new cells, if any, as well as cells range parameters
The NM provides the LC with the geographical areas related to the cells operating on LSA frequencies that have been removed from the network, if any
The NM provides the LC with the geographical areas related to the cells operating on LSA frequencies and whose parameters have been modified, if any
Note: The NM does not need to inform the LC when parameters of cells operating on LSA frequencies have been modified within the constraints provided by the LC
Step 2 (M)
The LC computes the constraints on parameters of cells operating on LSA frequencies that need to be satisfied in order to satisfy current LSA spectrum resource usage by incumbents and taking into account the ranges on parameters provided by the NM to satisfy LSA Licensee requirements
Step 3 (M)
The LC provides the NM with the constraints on cells parameters
Step 4 (M)
The NM reconfigures cells utilizing LSA spectrum resources, if necessary
Step 5 (M)
The NM confirms to the LC that the necessary configuration changes have been applied
Ends when
The NM has received the constraints on cells parameters and applied the necessary configuration changes
Exception
The LC loses connectivity with the LR
The configuration of the affected cells is not successful
Post-conditions
The NM is able to properly configure and activate new cells that are using LSA spectrum resources, using the constraints on cells parameters provided by the LC
The NM is able to properly reconfigure existing cells that are using LSA spectrum resources, using the updated constraints on cells parameters provided by the LC
Traceability
REQ-LC-IRP-SC2-FUN-005, REQ-LC-IRP-SC2-FUN-006, REQ-LC-IRP-SC2-FUN-007, REQ-LC-IRP-SC2-FUN-008

69. Use Cases for Scenario 2 (Loss of Connectivity with the LR)
Use case stage
Evolution/Specification
Goal
To provide the NM with default constraints on parameters of cells operating on LSA frequencies, following a loss of connectivity with the LR
The LC has received a confirmation from the NM that the necessary configuration changes have been applied
Actors and Roles
The function in the LC providing constraints on parameters of cells operating on LSA frequencies to the NM taking into account the related ranges provided by NM and the LSRAI provided by LR
The function in the NM providing a confirmation that the constraints are satisfied
Telecom resources
NM, LC
Assumptions
Connectivity between NM and LC is established
Connectivity between LR and LC is established
The LC has the functionality to convert LSRAI and parameters ranges provided by NM to constraints on some parameters of cells operating on LSA frequencies and to inform the NM about changes on those constraints
The LC has been configured with a fall-back measure (such as one of the measures described in Annex D of [3]), to execute in case of loss of connectivity with the LR
Pre-conditions
The LR, LC, NM and MFCN are set up and running
The NM has access to the list of cells operating on LSA frequencies
The LC is configured with default LSA spectrum resource availabity information, intended to be used when connectivity is lost with the LR
Begins when
The LC loses connectivity with the LR
Step 1 (M)
The LC asks to the NM the list of cells operating on LSA frequencies to the LC, as well as ranges for cells parameters
Step 2 (M)
The LC computes the default constraints on parameters of cells operating on LSA frequencies, according to the fall-back measure configured at the LC and taking into account the ranges on parameters provided by the NM
Step 3 (M)
The LC provides the NM with the new constraints on parameters
Step 4 (M)
The NM reconfigures cells operating on LSA frequencies, if necessary
Step 5 (M)
The NM confirms to the LC that the necessary configuration changes have been applied
Ends when
Exceptions
The configuration of the affected cells is not successful
Post-conditions
The NM is able to use LSA spectrum resources according to the updates provided by the LC
Traceability
REQ-LC-IRP-SC2-FUN-005, REQ-LC-IRP-SC2-FUN-006, REQ-LC-IRP-SC2-FUN-007, REQ-LC-IRP-SC2-FUN-008

70. System Context for Scenario 1
The LC and NM can play both the roles of IRPAgent and IRPManager for operations and notifications of the LSA IRP
IRPAgent
IRPManager LC NM
Type 7
interface
LC IRP
OperationsInvokedByNM
NotificationsEmittedByLC
OperationsInvokedByLC
NotificationsEmittedByNM

71. System Context for Scenario 2
The LC and NM can play both the roles of IRPAgent and IRPManager for operations and notifications of the LSA IRP
IRPAgent
IRPManager LC NM
Type 7
interface
LC IRP
OperationsInvokedByNM
NotificationsEmittedByLC
OperationsInvokedByLC
NotificationsEmittedByNM

72. Summary
LAA: the operation of LTE in unlicensed spectrum as a secondary cell through carrier aggregation
The use of LTE in unlicensed spectrum can serve as a useful additional tool by operators to maximize the value they can provide to users
The core of the activity of the operators remains anchored to the licensed spectrum
A majority of sources providing evaluation results showed
at least one LBT scheme for LAA that does not impact Wi-Fi more than another Wi-Fi network
The LBT scheme and/or parameters shown by different sources to not impact Wi-Fi more than another Wi-Fi network may be different
When an appropriate channel access scheme is used, it is feasible for LAA to achieve fair coexistence with Wi-Fi, and for LAA to coexist with itself based on the evaluated scenarios
The key parameters of the LBT scheme such as contention windows and defer periods should be configurable within limits to enable fair coexistence with other technologies operating in unlicensed spectrum