IPC Definitions - January 01, 2012
H04M - Definition
This subclass covers:
Telecommunication systems including subscriber equipment and exchanges, e.g.
Telephonic communication systems combined with other electrical systems;
Testing arrangements peculiar to telephonic communication systems.
Relationship between large subject matter areas
With regard to mobile telephony, H04M covers communication systems using wireless extensions, i.e. wireless links without selective communication, e.g. cordless telephones, which are covered by group H04M 1/72, whereas H04W covers communication networks for selectively establishing one or a plurality of wireless communication links between a desired number of users or between users and network equipments, for the purpose of transferring information via these wireless communication links.
With regard to VoIP (Voice over Internet Protocol), voice is considered in this context to be a specific form of "digital information". Since the Internet Protocol and IP networks are classified in H04L (H04L 12/00, Data switching networks and H04L 29/02, Communication control), the transmission of voice over IP networks should be classified in H04L.
When VoIP is used to emulate or simulate services, the service, as presented to the user, is still classified in H04M. Any implementation details are however classified in H04L. For example, SPIT and SPAM prevention in VoIP should be classified in H04M 3/436 or H04M 1/663.
VoIP is not covered by any single class, subclass, group or subgroup but rather classified as evolution of existing technologies. Therefore, aspects of VoIP are not only classified in H04M and H04L but also in other classes which have been used for classification of aspects related to telephonic communication, H04M, and transmission of digital information, H04L, such as by the Internet protocol.
References relevant to classification in this subclass
This subclass does not cover:
Circuits for controlling other apparatus via a telephone cable and not involving telephone switching apparatus | G08B, G08C, G08G |
Wireless communication networks | H04W |
Attention is drawn to the following places, which may be of interest for search:
Counting mechanisms | G06M |
Multiplex transmission between switching centres | H04J |
Selecting | H04Q |
Transducers | H04R |
Information storage based on relative movement between record carrier and transducer | G11B |
In this subclass, the following terms or expressions are used with the meaning indicated:
Subscriber | General term for a user of terminal equipment, e.g. for the user of a telephone set, or for any equipment used by subscribers, e.g. telephones for public use. |
Substation | Subscriber or monitoring equipment which may connect a single subscriber to a line without choice as to subscriber. |
Satellite | A kind of exchange the operation of which depends upon control signals received from a supervisory exchange. |
Switching centres | Include exchanges and satellites. |
Exchange | Synonym for telephone switch |
Voice mail system | A centralized system for managing telephone messages for a large group of users. |
PSTN | Public Switched Telephony Network. |
ISDN | Integrated Services Digital Network. |
ISUP | ISDN User Part. |
SIP | Session Initiation Protocol. |
H.323 | A standard protocol used for Packet-Based Multimedia Communications Systems. |
CTI | Computer telephony integration. A technology that allows interactions on a telephone and a computer to be integrated or co-ordinated. Common application interfaces and protocols for monitoring and controlling calls comprise Computer Supported Telecommunications Applications, CSTA, Java Telephony Application Programming Interface, JTAPI, Telephony Server Application Programming Interface, TSAPI, or Telephony Application Programming Interface, TAPI. |
Gatekeeper | A gatekeeper provides a number of services to terminals, gateways and devices, e.g. endpoint registration, address resolution, admission control and user authentication. |
Call agent | A call agent handles specific services to users e.g. alert the called party, send and receive voice data. |
IMS | IP Multimedia Subsystem. An architectural framework for delivering internet protocol, IP, multimedia to a mobile user. |
Softswitch | A central device in a telephone network which connects calls from one phone line to another, e.g. control connections at the junction point between circuit and packet networks. |
PBX | Private Branch Exchanges, e.g. for making connections among the internal telephones of a private organization. |
xDSL | Digital Subscriber Line. A family of technologies that provides digital data transmission over the wires of a local telephone network. |
Party line system | An arrangement in which two or more customers are connected directly to the same link or circuit. |
SPAM | The abuse of electronic messaging systems to send unsolicited bulk messages indiscriminately. |
SPIT | Spam over Internet Telephony, i.e. unwanted, automatically dialled, pre-recorded phone calls using Voice over Internet Protocol, VoIP. |