Signaalinkäsittely- ja tietokonetekniikan laboratorio

Signaalinkäsittely- ja tietokonetekniikan laboratorio

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2000

# Conferences

1 H. Mäntylä, "Evaluation of access network modifications required by the introduction of VDSL," to be presented at European Conference on Networks & Optical Communications, NOC 2000, Stuttgart, Germany, June 2000.

1999

# Conferences

5 J. Helenius, Y. Liu, M. Renfors, and T. Laakso, "Analysis of VDSL capacity based on channel measurements," in Proceedings Broadband Access Conference, BAC´99, Cracow, Poland, pp.160-166, October 1999.

4 Y. Liu, T. Laakso, J. Helenius and M. Renfors, "VDSL capacity estimation based on in-field measurements," in Proceedings Fifth Baiona Workshop on Emerging Technologies in Telecommunications, Baiona, Spain, pp. 37-41, September 1999.

3 Y. Liu, J. Helenius, T. Laakso and M. Renfors, "Capacity estimation of VDSL Connections based on channel measurements," in Proceedings 1999 Finnish signal processing symposium, FINSIG´99, Oulu, Finland, pp.262-266, May 1999.

2 H. Mäntylä, P. Poikolainen, and T. Laakso, "Design of very high speed digital subscriber line (VDSL) networks,"in Proceedings 1999 Finnish signal processing symposium, FINSIG´99, Oulu, Finland, pp.257-261, May 1999.

Reports

1 H. Mäntylä, Design of very high speed digital subscriber line (VDSL) networks, Helsinki University of Technology, Laboratory of Telecommunications Technology, Report 4/99, 73 pages, Espoo 1999.
ABSTRACT:
The goal of this thesis was to find how to upgrade the present copper access network to a broadband VDSL network in the best possible way. Copper pairs connected to practically every household form one of the most common access networks in the field of telecommunications. The evolution of this copper based network into a broadband fiber network is a long process. Hybrid fiber-copper based solutions seem to offer a good way to upgrade the copper networks gradually towards all fiber networks.
Digital subscriber line (DSL) technologies offer a possibility to reuse part of the huge existing copper base for broadband connectivity. VDSL offers the most transmission capacity, planned to operate over very short copper loops of a few hundred meters. To be able to use VDSL, changes to current network topology are required. Fiber nodes have to be placed close to subscribers, meaning placing of active electronics in a possibly hostile environment and new fiber cable needs to be installed to connect these nodes to the other networks.
An access network model was used to study a few upgrade options that bring fiber into the access network. Rough cost estimates were used to calculate the costs of considered topologies. It was found out that the network upgrade requires big investments. Especially the topologies with high fiber penetration level become attractive only with high VDSL take rate. It was also shown that the effect of subscriber distribution is important when the recommendable upgrade strategy is decided.

1998

# Journals

1 T. I. Laakso and A. Gyasi-Agyei, "Design of optimal symmetric FIR receive filters", Electronic Letters, Vol. 34, No. 25, pp. 2375-2377, 10th Dec. 1998.
ABSTRACT:
A method for designing optimal symmetric odd-length finite impulse response digital receive filters is proposed. The filter jointly minimises the mean power of intersymbol interference and additive noise or interference under the constraint that the filter coefficients are symmetric. The method yields exactly symmetric filters with the same performance as the earlier unconstrained design but with a lower computational complexity.

Tämän sivun sisällöstä vastaa webmaster@wooster.hut.fi
URL: http://signal.hut.fi/tutkimus/vdsl/publications.html
Sivua on viimeksi päivitetty 29.5.2000.

#	*Conferences*
1	H. Mäntylä, "Evaluation of access network modifications required by the introduction of VDSL," to be presented at European Conference on Networks & Optical Communications, NOC 2000, Stuttgart, Germany, June 2000.

#	*Conferences*
5	J. Helenius, Y. Liu, M. Renfors, and T. Laakso, "Analysis of VDSL capacity based on channel measurements," in Proceedings Broadband Access Conference, BAC´99, Cracow, Poland, pp.160-166, October 1999.
4	Y. Liu, T. Laakso, J. Helenius and M. Renfors, "VDSL capacity estimation based on in-field measurements," in Proceedings Fifth Baiona Workshop on Emerging Technologies in Telecommunications, Baiona, Spain, pp. 37-41, September 1999.
3	Y. Liu, J. Helenius, T. Laakso and M. Renfors, "Capacity estimation of VDSL Connections based on channel measurements," in Proceedings 1999 Finnish signal processing symposium, FINSIG´99, Oulu, Finland, pp.262-266, May 1999.
2	H. Mäntylä, P. Poikolainen, and T. Laakso, "Design of very high speed digital subscriber line (VDSL) networks,"in Proceedings 1999 Finnish signal processing symposium, FINSIG´99, Oulu, Finland, pp.257-261, May 1999.
	*Reports*
1	*H. Mäntylä, Design of very high speed digital subscriber line (VDSL) networks, Helsinki University of Technology, Laboratory of Telecommunications Technology, Report 4/99, 73 pages, Espoo 1999.* ABSTRACT: The goal of this thesis was to find how to upgrade the present copper access network to a broadband VDSL network in the best possible way. Copper pairs connected to practically every household form one of the most common access networks in the field of telecommunications. The evolution of this copper based network into a broadband fiber network is a long process. Hybrid fiber-copper based solutions seem to offer a good way to upgrade the copper networks gradually towards all fiber networks. Digital subscriber line (DSL) technologies offer a possibility to reuse part of the huge existing copper base for broadband connectivity. VDSL offers the most transmission capacity, planned to operate over very short copper loops of a few hundred meters. To be able to use VDSL, changes to current network topology are required. Fiber nodes have to be placed close to subscribers, meaning placing of active electronics in a possibly hostile environment and new fiber cable needs to be installed to connect these nodes to the other networks. An access network model was used to study a few upgrade options that bring fiber into the access network. Rough cost estimates were used to calculate the costs of considered topologies. It was found out that the network upgrade requires big investments. Especially the topologies with high fiber penetration level become attractive only with high VDSL take rate. It was also shown that the effect of subscriber distribution is important when the recommendable upgrade strategy is decided.