Realizing CMMSS in Software

We have authored two pieces of software to demonstrate CMM SS both pieces taken together essentially represent the CMM SS entity depicted in Figure 5.5. The first component we authored was a PSTN IN call model written in C++. This call model reproduces the state machines for the originating and terminating halves of the Q.1204 BCSM, including all legal transitions between them. This software acted as an IN layer between a SIP proxy and the PSTN service platform (see Figure 5.5). The next piece...

Service Description and Call Flows

For each service we realized through CMM SS, we now present a detailed description and a relevant call flow. Note that in the call flow, SIP messages are reproduced in an abbreviated form for brevity, i.e., not all headers and bodies are shown. 5.5.3.1 Originating Call Screening (OCS) OCS is a service whereby the O_BCSM ensures that the caller is authorized to initiate a call to the dialed number (or the callee). The OCS service is accessed by arming the Collect_Info trigger (DP 5) of the...

General Architecture of the PSTN

Figure 3.1 depicts the general architecture of the PSTN. Figure 3.1 depicts the general architecture of the PSTN. Inter-Toll Trunks to Other Toll Tandem Offices Inter-Toll Trunks to Other Toll Tandem Offices Local Loop Voice Trunk SS7 Signaling Local Loop Voice Trunk SS7 Signaling Figure 3.1 A high-level PSTN architecture. Telephone users (also called end users or subscribers), in either homes or offices, connect to the telephone system through phones on their office desks or in their homes....

XML Schema for SMS to IM

< xs schema xmlns xs http www.w3.org 2 001 XMLSchema 8 namespace> < This import brings in the XML language attribute xml lang > < xs import 8 namespace 0 01 xml.xsd > < xs documentation xml lang en> Describes SMS to IM Schema. < xs documentation> < xs annotation> < xs element name sms type tns smsType > < xs complexType name smsType> < xs sequence> < xs element name DeliveryType type tns DeliveryType maxOccurs unbounded > < xs element name IM type xs...

Service Architecture for the Cellular Public Switched Telephone Network

Until recently, the cellular network expanded with unprecedented growth. In 1984, there were 92,000 U.S. cellular subscribers, compared to approximately 140 million U.S. subscribers on December 31, 2002 FCC03 . Clearly, the cellular network is an important component of the PSTN. The current generation of the cellular network is referred to as 2G, short for second-generation cellular network. 2G is a digital voice network however, its endpoints are not Internet capable. It provides mobility and...

The Intelligent Network

The IN is an architectural concept it provides for real-time execution of network services and customer applications in a distributed environment consisting of interconnected computers and switching systems ITU92a, FAY96 . Until the advent of the IN, services were intimately tied to the switches and were not interoperable across vendor boundaries. The IN decoupled and distributed the call control and service execution to separate network elements call control took place on switches and the...

XML Schema for PSTN Events

< xs schema xmlns xs http www.w3.org 2 001 XMLSchema < This import brings in the XML language attribute xml lang > < xs import 8 namespace 001 xml.xsd > < xs annotation> < xs documentation xml lang en> Describes SPIRITS events. < xs documentation> < xs annotation> < xs element name spirits-event < xs complexType name SpiritsEventType> < xs sequence> < xs element name Event type tns EventType minOccurs 1 maxOccurs unbounded > < xs any namespace other...

Requirements of a Telecommunications SOA

Unarguably, the intelligence in the telecommunications networks continues to move out to the edges. Early analog phone systems were completely centralized. Call processing and service execution were often intertwined and occurred on centralized platforms owned by the telephone company, and also often used networks owned by the same telephone company. Digital switching systems coincided with the separation of call signaling from service execution (the IN concept). The intelligence was more...

CMMSS Architectural Model

Figure 5.7 depicts an architectural model for the IN service control based on our approach. On both the originating and terminating sides, a CMM SS entity is assumed to be present (it could be a proxy or a B2BUA). In the figure, we implicitly assume that one of the two endpoints involved in a session is on the PSTN, but this need not be the case. We have done so to provide a context for understanding the workings of CMM SS. CMM SS does, however, require that at least one endpoint be on the...

XML schema definition

The SPIRITS payload is specified in XML this section defines the base XML schema for documents that make up the SPIRITS payload. All SPIRITS entities that transport a payload characterized by the MIME type MUST support documents corresponding to the base schema below. Multiple versions of the base schema are not expected rather, any additional functionality (e.g., conveying new PSTN events) must be accomplished through the definition of a new XML namespace and a corresponding schema. Elements...

Applying the Mapping

To apply the mapping between the SIP state machine and Q.1204 BCSM, we followed the CMM SS technique and algorithms listed in Section 5.3. The SIP state machine corresponds to the F domain and the Q.1204 BCSM corresponds to the L domain. The states of FM need to be mapped into L such that we satisfy Equation 5.4. Because F and L contain a different number of states the Q.1204 PSTN IN call model consists of 19 states and 35 transitions (11 states and 21 transitions in the originating BCSM, and 8...

Notification of Missed Calls

IM is a service that is not generally associated with the wireline PSTN, although the cellular PSTN has supported a similar service in the form of SMS for some time. (To be pedantic, differences exist between IM and SMS. For one, SMS messages are limited to 160 to 200 characters, whereas IM systems in deployment today are capable of carrying larger messages. Furthermore, the network stores an SMS for later delivery if the recipient is not able to get the message in real time. IM systems, on the...

Constructing a Telecommunications Smart Space

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Recall that in a smart space, one world senses and controls the other one. The UA running on the Internet interfaces with the PSTN to subscribe to a set of events that it is interested in. The EM saves this subscription in persistent store. When such an event is published in the PSTN, the EM runs the selection process using the published event and the policies stored for the consumer. If the selection process results in a match, the consumer's UA is notified. The UA thus senses and controls the...

Conclusions

Over the course of their respective lifespan, the public switched telephone network PSTN and the Internet have evolved in divergent ways. The PSTN has been characterized by centralized control of network resources where the intelligence required to process the information resides in the core of the network. The Internet espoused a view that was completely opposite. The network itself was simply considered a transport to move information in the form of bits toward the edges, where more powerful...

Acronyms

Event Detection Point Notification Event Detection Point Request International Mobile Subscriber Identity Intelligent Network Application Protocol International Telecommunications Union Multipurpose Internet Mail Extensions Mobile Station or Mobile Subscriber Services in the PSTN IN Requesting InTernet Services Trigger Detection Point Notification Trigger Detection Point Request

Masking Uneven Conditions

The rate of penetration of pervasive computing technology will vary considerably. The capabilities of entities that provide services to users invisibly will vary considerably. One way to reduce the amount of variation observed by users is to have their computing space compensate for dumb environments in essence, provide a canonical representation of their computing space and ensure that a service, if it is operating in a nonfriendly environment, at least tunes its behavior to fit the...

Design of the EM

The EM is a critical piece in our architecture. All events published in the system by multiple event sources arrive at the EM, where they are mediated. Mediation consists of running a selection process on the event to determine if a consumer is interested in receiving a notification of that class of event. If so, the EM constructs a SIP notification request and dispatches it toward the consumer in a secure fashion. If the selection process did not result in an interested consumer, the event is...

Mapping SIP Protocol State Machine to OBCSM

The 11 PICs of O_BCSM come into play when a call request SIP INVITE message arrives from an upstream SIP client to an originating SIN-enabled SIP entity running the IN call model. This entity will create an O_BCSM object and initialize it in the O_NULL PIC. The next seven IN PICs O_NULL, AUTH_ORIG_ATT, COLLECT_INFO, ANALYZE_INFO, SELECT_ROUTE, AUTH_CALL_SETUP, and CALL_SENT can all be mapped to the SIP Calling state. Figure 5 provides a visual map from the SIP protocol state machine to the...

CMMSS Considerations

When interworking between Internet telephony and PSTN IN networks, the main issue is to translate between the states produced by the Internet telephony signaling and those used in traditional IN environments. Such a translation entails attention to the considerations listed below. In Service Platforms SCP, SN, AD, IN Basic Call State Machines and Transitions Approximates a Traditional Swith IN Basic Call State Machines and Transitions Approximates a Traditional Swith 5.4.1.1 The Concept of a...

Service Architecture for Traditional Telephone Network

Scp Sdp Smp

The service architecture for the traditional telephone network wireline and wireless is defined around the Intelligent Network IN FAY96 . IN is a conceptual architecture that separates the call control from the service execution. Figure 2.1 shows a simplified IN architecture. In reality, there are more IN entities than depicted in Figure 2.1, but for our discussion, the ones depicted in the figure suffice. Subscribers use telephonic devices that are connected to a telephone switch called the...

Localized Scalability

Scalability is a critical problem in pervasive computing. Depending on the specifics of the smart space implemented, the intensity of interaction among cooperating entities may increase. Although this may be acceptable for a smart space that is confined to a small area, it is prohibitive for one that spans geographical distances. The problem is further compounded if one or more of the cooperating entities are mobile and thus may be limited by the bandwidth, energy, and computing power. In...

Conclusion

We have implemented PSTN-originated crossover services for the wireline GUR03a and cellular GUR04d, GUR05a components of the PSTN. Our implementation will be discussed in detail in the next chapter, where we will highlight its applicability to ongoing research in the area of pervasive computing. It is important to note that the ontology we have described is not limited to PSTN events culled from the BCSM. The methodology presented here is independent of any call model just an agreement is...

List of Abbreviations and Symbols

Data enhanced Second Generation network Third Generation Partnership Project Call Model Mapping with State Sharing Common Object Request Broker Architecture CTI Computer Telephony Integration GPS Geographical Positioning System HTTP Hypertext Transfer Protocol IANA Internet Assigned Numbers Authority IETF Internet Engineering Task Force IM Instant Message or Instant Messaging INAP Intelligent Network Application Part IP Internet Protocol, also Intelligent Peripheral ITU International...