The Mythical IUT
How to support automatic testing in standardization
OBSAI conformance testing as an example
TTCN-3 User Conference
6-8th June 2005
Sophia Antipolis, France
TTCN-3 User Conference, 6-8 June 2005
Hannu Rytilä
Contents
> Testability in general
> Automated testing
> Design for testability
> Standardization for testability
> OBSAI
> Testability in OBSAI
> Achievements
> Future work
> Lesson learned
TTCN-3 User Conference, 6-8 June 2005
Hannu Rytilä
The Mythical IUT
Just
test it!
TTCN-3 User Conference, 6-8 June 2005
Hannu Rytilä
Testability in General
> Control: The better we can control it, the more the testing can be
automated and optimized.
> Visibility: What we see is the what we can test.
> Operability: The better it works, the more efficiently it can be
tested.
> Simplicity: The less there is to test, the easier we can test it.
> Understandability: The more information we have, the smarter we
test.
> Suitability: The more we know about the intended use of the IUT,
the better we can organize our testing to find important bugs.
> Stability: The fewer the changes, the fewer the disruptions to
testing.
[Bach, James (1999). “Heuristics of Software Testability]
TTCN-3 User Conference, 6-8 June 2005
Hannu Rytilä
Automated Testing
> Automated test generation
> Automated test adaptation
> Automated test execution
> Automated verification of the results
TTCN-3 User Conference, 6-8 June 2005
Hannu Rytilä
OBSAI Open Base Station Architacture Initiative
www.obsai.org
>
OBSAI is an organization
formed among leading base
station vendors, module and
component manufacturers to
create a set of open
specifications for base
station architecture.
>
Promotor Companies:
Hyundai Syscomm, LG
Electronics, Nokia,
Samsung, ZTE
>
118 members
TTCN-3 User Conference, 6-8 June 2005
Hannu Rytilä
Goals of OBSAI
> Define and agree on Base Station Architecture on a
modular level
> Develop and provide interface specifications
between the main functional modules
> An OBSAI base station consists of
– Cabin with standardized backplane
– A set of modules
“Make it like a PC”
TTCN-3 User Conference, 6-8 June 2005
Hannu Rytilä
Simplified OBSAI Architecture
RP2
Network
Interface
TRANSPORT
MODULE
RP3
BASEBAND
MODULE
RF
MODULE
Air
Interface
RP1
Control
Traffic
Clock
CONTROL & CLOCK
MODULE
© OBSAI TWG
TTCN-3 User Conference, 6-8 June 2005
Hannu Rytilä
Transport Module
> External Network Interface Functions
> Internal Networking Functions (IP & CML Router)
> QoS Functions
> Network Interface Protocol Termination
> Synchronization Functions
> OAM&P Functions
> Security Functions
RP2
Network
Interface
TRANSPORT
MODULE
RP3
BASEBAND
MODULE
RF
MODULE
Air
Interface
RP1
CONTROL & CLOCK
MODULE
TTCN-3 User Conference, 6-8 June 2005
Hannu Rytilä
Control
Traffic
Clock
Baseband Module
WCDMA
>Channel encoding/decoding
>Interleaving
>Rate matching
>Multiplexing/demultiplexing
>Spreading
>Power weighting & summing of
physical channels
>RAKE reception
>MUD alternative
>Interference cancellation
>Interference Rejection Cancellation
>Frame protocol processing
>Higher layer processing (L2 & L3)
>CRC
GSM
>Channel encoding/decoding
>Interleaving/de-interleaving
>Bit detection
>Frequency hopping
>Ciphering/deciphering
>DL diversity transmission (MIMO, etc.)
>UL diversity reception, IRC reception,
SA reception
>Protocol frame processing
RP2
Network
Interface
TRANSPORT
MODULE
RP3
BASEBAND
MODULE
Air
Interface
RP1
CONTROL & CLOCK
MODULE
TTCN-3 User Conference, 6-8 June 2005
RF
MODULE
Hannu Rytilä
Control
Traffic
Clock
RF Module
>
>
>
>
>
>
>
>
>
>
>
>
>
>
Modulation
D/A & A/D conversion
Up/down conversion
Carrier selection
Linear power amplification
Antenna interface
Transmit / receive RF filtering
RF combining
Transmit / receive RF filtering
Diversity transmit
Diversity receive (duplexing, etc.)
Low noise amplification
Peak power reduction
OAM&P Functions
RP2
Network
Interface
TRANSPORT
MODULE
TTCN-3 User Conference, 6-8 June 2005
RP3
BASEBAND
MODULE
RF
MODULE
Air
Interface
RP1
CONTROL & CLOCK
MODULE
Hannu Rytilä
Control
Traffic
Clock
Control & Clock Module
> Congestion Control
> Admission Control
> BTS Level OAM&P Functions
> BTS Configuration Management and Control
> Radio Resource Management
> Multi-vendor Configurations
> RF Scheduling
RP2
> Iub/Abis Signalling Termination
Network
Interface
TRANSPORT
MODULE
RP3
BASEBAND
MODULE
Air
Interface
RP1
> System Clock Generation and Distribution
CONTROL & CLOCK
MODULE
TTCN-3 User Conference, 6-8 June 2005
RF
MODULE
Hannu Rytilä
Control
Traffic
Clock
Logical Interfaces
RP1
RP2
RP3
Management-plane
User-plane
App: type mapping
Control-plane
Pv6 (IPv4 opt)
Transport: Routing
IPv6 (IPv4 opt)
802.3 MAC
Data Link: Framing
802.3 MAC
802.3 100 Base-TX
(1000 Base-TX opt)
802.3 100Base-TX
2 level framing
9 to 9 addressing
CML 1.6 Gb/s
TTCN-3 User Conference, 6-8 June 2005
Hannu Rytilä
Testability in OBSAI comes from:
> Clearly defined IUT
> Clearly defined interfaces
> Clearly defined test setups
> Control
– Test mode
– Test categories
– Test functions
– Test control messages
TTCN-3 User Conference, 6-8 June 2005
Hannu Rytilä
The IUT
>The IUT is always an OBSAI
module.
>A reference design shall be
offered to get compliance for a
chipset.
>Every module have to support
RP1 interface
>RP1 was selected as standard
test control port.
TTCN-3 User Conference, 6-8 June 2005
Hannu Rytilä
SA
OBSAI tester
OAM&P
messages
Test
functionality
Module
agent
test
adapter
HW
IUT: OBSAI module
proprietary test control messages
TTCN-3 User Conference, 6-8 June 2005
RPn
TE
RP1/ethernet
TM
RPn
OBSAI
test
control
messages
RP1/ethernet
Generic Test Setup
Hannu Rytilä
Test Mode and Test Categories
module startup and
module ready indication
normal operational mode
<setTestModeReq> “on”
test mode
<setTestModeReq>
“off”
<setTestModeReq>
“on”
category 1
s
category 2
category 3
TTCN-3 User Conference, 6-8 June 2005
Hannu Rytilä
Test Categories
Normal
op
Cat1
Cat2
Cat3
…
Function 1
M
M
M
M
M
Function 2
M
O
O
O
O
Function 3
M
O
M
O
O
…
M
O
O
Function n
M
O
M
Functions
Normal functions
O
O
Test functions
Test func.1
M
Test func 2
M
M
Test func 3
M
Test func m
M
M
TTCN-3 User Conference, 6-8 June 2005
Hannu Rytilä
Test Functions
>Implemented by the Module Agent
>Activation of a loopback
>Activation of a test signal
Implemented
by the
Module Agent
>Activation of a measurement
>Activation of a procedure
TTCN-3 User Conference, 6-8 June 2005
Hannu Rytilä
Test Control Messages
>SOAP Messages
>Valid only in test mode
>Activation of test functions
From the Test
Manager
>Triggering of standard
procedures
>Retrieval of measurements
>State & event indications
to the Module
Agent
TTCN-3 User Conference, 6-8 June 2005
Hannu Rytilä
Achievements so far
> The 1st release of OBSAI specifications includes
– Compliance process specification
– Test messages specification
– Generic conformance test specification
– Several focused test specifications
> Modules of different vendors can be tested with
generic testers?
Plug and test approach
TTCN-3 User Conference, 6-8 June 2005
Hannu Rytilä
Future work for release 2
> More formal approach is needed
– Formalization of interface specifications
– Formalization of configuration management
– Formalization of test specifications
– Provide TTCN-3 test suites
TTCN-3 User Conference, 6-8 June 2005
Hannu Rytilä
Lesson Learned
> Whatever you specify, make it testable by:
– specifying visibility
• interfaces
• points for observation
– specifying controllability
•
•
•
•
•
test setups
test clients, test agents
test control interfaces
test functions
test sequences
TTCN-3 User Conference, 6-8 June 2005
Hannu Rytilä
TTCN-3 User Conference, 6-8 June 2005
Hannu Rytilä