AMHS Performance

AMHS Implementation

WorkshopChennai, India

15th – 17th December 2008

List of Topics

• Concept of Performance

• Performance in Communication - RCP

• Aspects of AMHS Performance

• Performance Indicator

• Proposed Regional PI

• Other Issues

Concept of Performance

• “A major factor in determining the overall productivity of a system, performance is primarily tied to availability, throughput and response time.“

Concept of Performance

• For aviation, performance considerations are expected to be aligned to the end-to-end oriented, instead of component-oriented.

• Example – Required Navigation Performance (RNP)– Required Communication Performance (RCP)– Required Surveillance Performance (RSP)

Concept of Performance

• Performance is tightly related to implementation where regional-groups have to coordinate with.

• Some aspects of performance should be left to the States as local matters.

Performance - RCP

• Required Communication Performance (RCP)– Defined by ICAO’s OPLINKP;– Defined with respect to the operational

performance instead of the technical performance (technology independent);

Performance - RCP

– Is strongly recommended, but it is not mandatory

– is mainly defined in terms of time, especially response time, aspect of performance (no through-put aspect)

– The RCP types are defined by the ICAO (OPLINKP), the specific values of the RCP types are to be selected for any specific ATM services provided, e.g. Separation Assurance, by concerned groups for any specific airspace.

Performance - RCP

Aspects of AMHS Performance

• Objectives of AMHS Performance Assessment– Regional Assessment of Performance

• Some Indicators of AMHS Performance– Synonyms – Quality of Service

Aspects of AMHS Performance

• Proposed Activities of AMHS Performance Assessment– Identifying/Confirming the Performance

Indicator– Setting Performance Target (during the

planning stage)– Measuring Performance– Evaluating Performance (at the operational

stage)

Category of AMHS Performance

• Demand of messaging– indicates the number of messages received and sent

at each AMHS server

• Capacity of AMHS Server– indicates the ability to handle the number of

messages in the service.

• Time efficiency (delay)– indicates the time interval required to transmit

individual message.

• Reliability

Performance Indicators (PI)

Category Candidate Indicator

Demand of messaging

Inbound (receiving) demand

Outbound (sending) demand

Capacity of AMHS Throughput

Time efficiency Delays in transmission

Reliability Quality on message delivery (# of Undelivered messages)

Quality of delivered message (# of Error messages)

Demand of messaging

• Inbound Demand– Number of messages an AMHS system

expected to receive during certain interval.

• Outbound Demand– Number of messages an AMHS system

expected to send during certain interval

• The peak demands of inbound and outbound messaging may differ during the operation.

Demand of messaging

• The inbound message demand at one AMHS server may influence the transmission of other AMHS servers.

• The inbound/outbound demand is a good estimate of the capacity of the system.

• The regional messaging demands is not necessary, however the statistics of messaging demand as a whole in the region will be useful.

Capacity of AMHS server

• The capacity of AMHS server indicates the ability to handle the number of messages in the service (Throughput).

• It is the States’ responsibility to identify the capacity of their AMHS servers

Time Efficiency

• The time for transmission (delay) indicates the time interval required to transmit individual message.

• Several values can be measured:– Time from server output queue to server input

queue– Time from server input queue to server storage– Time from server storage to server output queue

Reliability

• There are two possible AMHS performance indicators related to the reliability– Quality of message delivery - how many

messages out of the total messages sent are delivered/undelivered to the intended recipients

– Quality of delivered messages - how many messages out of the messages received have/does not have the (detected) errors

Proposed Regional PI

• Inbound Demand (at Receiver)– Using the inbound demand at receiver, the sender

can adjust the parameters for sending message accordingly.

• Quality on Message Delivery– The number of NDRs can be indicator of this

aspect

• Quality of Delivered Message– The number of messages with detected errors can

be indicator of this aspect.

Proposed PI For State

• At State Level – Local AMHS server– Demand – both inbound and outbound

demand– Capacity – using peak inbound and outbound

demand– Time Efficiency – various delays value– Reliability – quality of message delivery and

delivered messages

Target of PI

• All PI should have target whether they are regional or state.

• The target should be agreed by all members.

• For Regional PI, the indicator should be measured and reported periodically.

• Example:– Quality of message delivery – the rate of NDRs

message should be less than or equal to 10^(-4)

Other issues to consider

• AMHS performance assessment during transition period.

• AMHS performance assessment across Regional boundaries.

• Performance assessment at Network/Data Link level (Lower level)

Thank you