Wireline Access Research Articles

The Layer-Independent Descriptor Concept

With the fast improvements of broadband technologies, more and more demanding services can be accessed. Broadband access is supported by a range of wireless and wireline technologies. Well known representatives are WLAN and UMTS for wireless and xDSL for wireline access. However, the highly varying nature of wireless channels and the crosstalk behavior of the DSL channel are typical traits, and most challenging to combat. Moreover, the stringent requirements of real-time applications require enhancements in service delivery. The tremendous interest in communication has driven the deployment of new access systems. Hence, for the End-to-End point of view, the service delivery multifarious due to the heterogeneity of the underlying transport network. Therefore, to enable a transport independent path set-up, application and network properties that may influence the user-perceived quality need to be unified. Thereby, media scalability plays a key role. Recently, cross-layer communication is getting acceptance as a method that efficiently increases the system performance. Unlike previous works that mainly addressed the issue of application based feedback, we focus on the information that the application can provide to guide the network for local stream management. We present the necessary set of Application Layer information for scalable audiovisual streams to offer individual QoS, at lowermost packet overhead. Finally, we show the sustainable gain in system performance based on a DSL use-case.

Balanced Capacity of Wireline Multiuser Channels

This paper analyzes the multiuser capacity of Gaussian frequency-selective wireline multiaccess channels. Both the uplink (multiple-access channel) and downlink (broadcast channel) capacity regions are considered. The concept of balanced capacity is introduced to characterize the multiuser channel performance. Algorithms for the computation of the balanced multiuser capacity (and the associated power allocations) are proposed for an arbitrary number of users. The optimal power allocation in a K-user memoryless Gaussian channel is analyzed in detail, and an extension to intersymbol interference channels is given with various kinds of power constraints. Results are provided for a wireline access network with 20 users.

Architectures and design considerations for wireline ΣΔ modulators beyond ADSL

In this paper we discuss design considerations for sigma–delta modulators (ΣΔMs) aimed at high-linearity high-speed A/D conversion, as required in emerging wireline access applications. In order to achieve resolutions in the range of 12–15 bit with sufficiently low oversampling ratio, we analyze the performance of a family of high-order cascade architectures in a low-voltage deep-submicron scenario. We show that, after proper architecture selection, guided by a simple power estimation method, these ΣΔMs are good candidates to achieve ADSL performances in coming CMOS processes. Experimental results on a prototype for ADSL+ applications designed in 2.5-V 0.25-μm CMOS suggest the possibility of programming or reusing the design for other telecom applications, thanks to the easiness to expand or shrink this family of cascade ΣΔMs to other orders. Estimated performance of the adapted prototype for ISDN, SDSL, and VDSL applications provides promising results.

SIP-based services architecture across wireless and wireline access

There are strong market and industry drivers to support a common set of end-user services ubiquitously across several wireline and wireless access technologies: UMTS/CDMA, 802.11 WLAN, Bluetooth <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∗</sup> WLAN, DSL, and cable TV/packet cable. Currently, service providers must use different services architectures for providing the same end-user services on different access networks. A common Session Initiation Protocol (SIP)-based architecture that can support a wide range of text, voice, and video services has been developed; it is based on the 3GPP/3GPP2 IP Multimedia Subsystem (IMS) standard. With a few minor extensions, the IMS services architecture can be used to support services across wireline and wireless access networks.

A General Framework for Competitive Analysis in Wireless Telecommunications

A General Framework for Competitive Analysis in Wireless Telecommunications

Simultaneous baseband and RF optical modulation scheme for feeding wireless and wireline heterogeneous access networks

In this paper, a novel modulation scheme that allows broad-band optical data transmission at both baseband and millimeter-wave RF carriers at twice the local-oscillator frequency is investigated. The dispersion-induced carrier suppression may be overcome by properly setting the optical transmitter parameters. Three different configurations for the modulation scheme are modeled and simulation and experimental results are provided. The key parameters of these configurations are optimized in order to achieve the best performance in broad-band heterogeneous millimeter-wave wireless and wireline access networks.

The correlation effects on service control point response time

AbstractAs the centralized database for the integration across multiple wireless tiers and wireline access, traffic design considerations for SCP performance measurement are of great important in the personal communications era. By neglecting the effect of disk access time, the SCP response time R includes the SCP processing time P and signalling link delay L only. A bivariate normal distribution has been proposed for modelling (P, L) such that some statistical estimations of L given P can be conveniently obtained in different combination of SCP processing load and link utilization. Further, the correlation effects of (P, L| P=p) on R are investigated. After a Tukey one degree of freedom test with one observation of μL|P=p per treatment (n=1) under different normalized processing times and correlations, the two‐factor ANOVA model becomes an interaction model without pure error effects due to the computed F* values being significantly greater than the critical F (0.95; 1, 11). Besides, rejection threshold criteria of SCP response time with minimum loss rate (0.01 per cent) of messages are proposed to ensure a good service quality of SCP.