Access to telecommunications networks in a multi-service environment by mapping and exchanging control message between CPE adaptors and access server

In current voice telephony, CATV, and wireless networks, traffic is channelized for both access and transport, requiring a dedication of a fixed bandwidth end-to-end for the duration of a service connection. This channelization is wasteful of resources where multiple services have varying demands for bandwidth and holding times, or a service generates traffic that is bursty in nature. The invention addresses these problems by providing flexible and adaptable multiservice access to the networks. Customer requirements are checked by monitoring traffic on a local access at a connection request and/or during the established connection, and local access is configured according to transmission requirements. Customer traffic is segregated and routed to the appropriate network. One of the embodiments uses 2B1Q line coding and implements a novel protocol to perform the functions of the invention.

FIELD OF INVENTION 
The present invention relates generally to communication between customer 
premise equipment (CPE) and telecommunication networks. In particular, it 
is directed to novel implementations of a multi-service platform in an 
ISDN-like environment which allows a plurality of CPEs accessing any 
services provided by a plurality of service providers which may utilize 
any of a plurality of telecommunications networks. 
BACKGROUND OF INVENTION 
Facsimile machines and other data handling customer premise equipment are 
introduced not only into offices but individual homes in great numbers. As 
personal computers are found in more homes, users of computer networks 
such as "Internet" by way of telephone networks through modems are 
increasing in phenomenal numbers. The majority of these data transactions 
through modems or fax machines use existing local exchange carrier 
networks for data transmission. Fax machines, computers, and telephone 
sets at a customer premise are connected by local access to a central 
telephone switching office. Local access is variously called a 
subscriber's loop, local loop, drop etc. In cases of CATV or wireless, 
local access is also called subscriber connection, wireless access etc. It 
has been shown that the majority access "Internet" by dial-up telephone 
connection. 
FIG. 1 shows how a telephone, fax, computer and other intelligent agents 
are typically connected through a publicly switched telephone network and 
data networks and their interconnections. Terminal equipment at a customer 
premise consist of a telephone set, fax machine, a personal computer etc., 
and are collectively called CPE which stands for customer premise 
equipment. CPE 10 is connected through inside wiring 12 at the customer 
premise and then through the feeder/distribution plant (also called 
subscriber's loop, local access loop) 14 to an access module (e.g. 
linecard) 16. The linecard is in turn connected to a local switch 18 that 
is part of the public switched telephone network (PSTN) 20. PSTN operates 
in channelized mode and provides continuous connection to another 
subscriber 22. The telephone service is established through a connection 
protocol (e.g. dialup, on-hook/off-hook protocol) and upon connection 
provides fixed channelized bandwidth on a continuous basis for the 
duration of the call. A facsimile connection is essentially the same as a 
telephone connection with the exception of the presence of a modem 24 at 
each facsimile terminal. The figure also shows a connection involving a 
data network. For such a connection, the CPE (e.g. computer) also requires 
a telephone subscriber's loop to the PSTN by dialup service which connects 
to a data service provider 26 through its own subscriber's loop 28. The 
data service provider 26 then provides a data connection through a data 
network 30 to a database service or other data service subscribers. 
Computer connections are generally much longer in duration than voice or 
other connections. Computers perform data transactions in packets and 
their traffic is very bursty. The bursty traffic is more suitable for 
statistical multiplexing and is most efficiently handled by specially 
designed data networks such as packet switched networks. At present, 
however, all publicly switched traffic, data and voice, is sent over the 
subscriber's loop and interoffice trunking in a circuit switched network 
connection to destination customer premise equipment or to a data network. 
Multimedia broadband switched networks by the name of the "Information 
Superhighway" have been widely proposed. This superhighway may carry 
different types of traffic seamlessly, accepting voice, data and video 
information from any terminal and delivering it to any other terminals 
simultaneously. At present, however, different types of networks, both 
channelized and packetized, exist separately and independently. 
In circuit switched networks, a connection is maintained during the whole 
duration of a call through switches and other associated network elements, 
regardless of the type of the call. Only one circuit switched connection 
can be maintained for the call. No broadcast or multicast through the 
circuit switched network is possible. Today, telephone networks are 
becoming increasingly more occupied by data traffic which generates no 
additional revenues to the local exchange carriers. Furthermore, access to 
worldwide computer networks, such as "Internet" etc. is now being provided 
by commercial network service providers, such as "America Online", 
"SprintLink" etc. Using PSTN as the access, the network service providers 
provide access to various other private networks, academic networks etc., 
which contain vast numbers of databases for value added services. 
FIG. 2 shows diagrammatically how data networks such as "Internet" are 
accessed through a telephone subscriber's loop. An individual end user 
subscribes to the service of a commercial network service provider 40. 
Access to a data network is usually by dialling the telephone number of a 
commercial data network service provider using a modem. Thus the end user 
CPE 42 uses a modem and makes a dialup connection to a local switch 44 by 
a subscriber's loop 46. The local switch 44 makes an inter-office trunk 
connection 48 to a terminating local switch 50 within a PSTN 52. The 
terminating local switch connects through a local loop 54 and a 
terminating modem to a service provider 40. After a proper modem 
handshaking protocol, the user inputs the address of a destination such as 
the "Internet" server with whom he desires a connection. Data networks and 
database services are accessed using a TCP/IP protocol. The "Internet" 
packet is routed over a T-1 link 56 (or other facilities) to the Internet 
58. In this arrangement, the local switches 44 and 50 as well as the 
interoffice trunk 48 are occupied for the duration of the connection, 
which is usually measured in hours rather than the shorter holding time 
associated with voice calls which are measured in minutes. Consequently, 
very expensive common equipment in the PSTN is required for the duration 
of the "Internet" access, even during a period of inactivity by the end 
user. 
The use of a telephone network by network service users increases usage of 
the telephone network enormously without a proportionate increase of 
additional revenues to the telephone company. It is also cumbersome for an 
individual user to access various networks. It will be shown below that 
the present invention reduces this investment in the PSTN as well as 
enhances the capabilities of the overall global communications network. 
The U.S. Pat. No. 5,610,910, filed on Aug. 17, 1995 and issued on Mar. 11, 
1997 having a common inventor, describes a new access architecture which 
improves the access to telecommunications networks including various 
different types of networks. It involves a local access which determines 
the kind of service requested by a connection request and selects access 
directly to the network requested or a network which is decided upon 
preset conditions. 
The present invention expands on this access architecture and is directed 
to a novel implementation which allows efficient use by data and voice 
traffic of available bandwidth between CPEs and the telecommunications 
network in an ISDN-like environment. 
OBJECTS OF THE INVENTION 
It is an object of the invention to provide a method of and apparatus for 
utilizing efficiently the available bandwidth of the local access by voice 
and/or data traffic. 
It is another object of the invention to provide a method of and apparatus 
for allocating the available bandwidth as a whole or any specific subset 
to a service subscribed by the end user. 
It is a further object of the invention to provide a method of and 
apparatus for allocating dynamically a part of the available bandwidth to 
a specific service. 
It is yet another object of the invention to provide a method of and 
apparatus for simultaneous multiple service delivery over the same access 
network. 
It is still a further object of the invention to provide a method of and 
apparatus for routing traffic to an appropriate network or CPE device by 
identifying the type of requested service. 
SUMMARY OF THE INVENTION 
Briefly stated, according to one aspect, the invention is directed to a 
method of interfacing directly one or more CPEs with either or both PSTN 
and data networks by way of a CPE adapter, an access medium and access 
server. The method comprises steps of exchanging control messages between 
the CPE adapter and the access server to determine the type of service 
request. The method further comprises steps of mapping the control 
messages onto the access medium using either or both a channelized and a 
non-channelized format and selecting between a telephone interface 
connected to the PSTN or a data network interface connected to the data 
networks in response to the type of service request. 
According to another aspect, the present invention is directed to an access 
server for directly interfacing CPEs with PSTN or a data network by way of 
a CPE adapter and an access medium. The access server comprises a 
telephone interface unit to be connected to the PSTN and a data network 
interface unit to be connected to the data network. The server further 
includes a transceiver to be connected to the CPE adapter for exchanging 
end user's traffic and control messages therebetween, and a controller 
unit for selecting a connection of the transceiver either with the 
telephone interface unit or with the data interface network unit in 
response to the control messages. 
According to a further aspect, the present invention is directed to an 
access apparatus for interfacing CPEs and a telecommunications network 
which encompass PSTN and data networks in a multiservice environment. The 
apparatus comprises a CPE adapter to be connected to one or more CPEs and 
an access server having a telephone interface unit and a data network 
interface unit. The apparatus further includes a first transceiver in the 
CPE adapter and a second transceiver in the access server to be connected 
with one another by a pair of wires, the first and the second transceivers 
for exchanging control messages through a signalling channel. The 
apparatus also includes a controller for selecting either the telephone 
interface unit or the data network interface unit in response to the 
control messages. 
According to yet another aspect, the invention is directed to a CPE adapter 
for directly interfacing CPE with PSTN or a data network by way of an 
access server. The CPE adapter comprises a telephone interface unit to be 
connected to one or more analog CPEs and a data network interface unit to 
be connected to one or more data CPEs. The CPE adapter further includes a 
transceiver to be connected to the access server for exchanging control 
messages therebetween and a controller unit for selecting a connection of 
the transceiver either with the telephone interface unit or with the data 
network interface unit in response to the control messages.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF INVENTION 
This invention defines a new architecture between the CPE adapter and the 
access server and a new communications protocol between them. This new 
protocol introduces specific messages to facilitate appropriate routing of 
the requested services, negotiation of the bandwidth between the CPE 
adapter and the access server and so on, in response to specific service 
requirements. Some service information, for example