Feature Interaction:Feature Interaction:An Industrial An Industrial PerspectivePerspective

Greg UtasGreg UtasMay 17 2000May 17 2000

G.Utas - Feature Interaction: An Industrial Perspective - 000517 2

Topics

In the next decade, in emerging networks... Will the number of feature interactions increase or decrease?

Will the interactions become easier or more difficult to resolve?

New services in emerging networks are largely undefined, so... look at forces that affect new networks, and the characteristics of

new networks, to investigate these questions

G.Utas - Feature Interaction: An Industrial Perspective - 000517 3

Two definitions

Interaction: a relationship between two features running on behalf of the same user for example, the flashhook contention between POTS three-way

calling and call waiting

important interactions must be specified

Interworking: a relationship between two features running on behalf of different users for example, call completion to a busy subscriber

must be specified, because they usually involve different systems

G.Utas - Feature Interaction: An Industrial Perspective - 000517 4

Standards

More standards => more interactions and interworkings

Forces that create more standards include differentiation (competition)

interoperability (interworking)

not invented here

creating barriers to entry (protecting incumbents)

levelling the playing field (disrupting incumbents)

These forces will increase both the numberof interactions and their complexity.

G.Utas - Feature Interaction: An Industrial Perspective - 000517 5

Intelligent Network concepts

Service capabilities don’t specify services, but rather service building blocks

makes interactions more difficult because they cannot be resolved based on the specific services involved

Protocol independence services need not understand access (UNI) or interworking (NNI)

protocols

limits the range of services that can be developed

Application Programming Interfaces (APIs) AIN, TAPI => JAIN, JTAPI

Nothing fundamental has changed.

G.Utas - Feature Interaction: An Industrial Perspective - 000517 6

Home Call Server

In existing mobile networks, services run in the call server where the mobile was located when it originated or received its call service ubiquity; limited differentiation

Next generation mobile networks may separate the signalling and bearer paths signalling path goes to Home Call Server first, which runs services

bearer path may first go to Serving Call Server, for route optimization or location-based services

Separation of access provider and service provider

A Home Call Server increases the degree ofinteraction and interworking because of differentiation.

G.Utas - Feature Interaction: An Industrial Perspective - 000517 7

Intelligent terminals

The power of terminals (“clients”) increases, and so more features will be developed there...

But the network will still be involved: interworking

proxy (for unreachable terminals)

group services

stimulus signalling

security, performance, or revenue reasons

The number of interactions and their complexity increasesbecause of additional terminal-network interactions.

G.Utas - Feature Interaction: An Industrial Perspective - 000517 8

Downloadable services

Download services to terminals, SSPs, or SCPs for example, MExE and WAP for mobile terminals

Will probably be restricted to content-based services security and quality concerns

complexity issues, at least beyond the IN call model

Will probably be limited to servicesthat introduce few interactions.

G.Utas - Feature Interaction: An Industrial Perspective - 000517 9

Bearer path architecture

Addition of ATM and IP networks transcoding and adaptation must be negotiated

broadcasting (e.g. during mobile handover) requires special support

separation of signalling and bearer paths complicates call intercept (wiretap) requirements

multimedia, however, is a simple change to the connection object model

Interactions and interworkings become somewhatmore complex for connection oriented services.

G.Utas - Feature Interaction: An Industrial Perspective - 000517 10

Security and privacy

Often mentioned as issues for IP-based networks, but they even exist today privacy indicator for calling number

authentication, ciphering, and aliases (TMSIs) in GSM networks

Firewalls in IP-based networks are a new obstacle

Security and privacy are new dimensions that increasethe complexity of interactions and interworkings.

G.Utas - Feature Interaction: An Industrial Perspective - 000517 11

Quality

Increased differentiation

=> cursory interoperability

=> reduced quality of interactions and interworkings

Could this persist? for a while, if users or service providers lower expectations, but...

emerging products want content

established products want schedule

mature products want quality--assuming that maturity is reached

Reduced focus on quality => much less focus on interaction.Continued focus on quality => big focus on system integration.

G.Utas - Feature Interaction: An Industrial Perspective - 000517 12

Conclusion

More interactions, and more complexity, resulting from competition, which drives differentation

interoperability, driven by differentiation

services also being developed in terminals

new dimensions of bearer path design, security, and privacy

But will reduced quality expectations allowthe interaction “problem” to be largely ignored?