Flat Is Back: Toward the All-IP Mobile Network

Growing demand for packet applications, combined with faster radio access technologies, is accelerating the move to flat, all-IP mobile networks, finds the latest research report from Unstrung Insider.

Flat IP Architectures for Mobile Networks investigates flat architecture initiatives from across the wireless industry, as operators seek to lower costs, reduce system latency, and decouple radio access and core network evolution. The 30-page report also analyzes the strategies and product roadmaps of leading equipment suppliers looking to seize this disruptive opportunity to win market share.

Driving the market is widespread acceptance that today's hierarchical architectures, conceived in the circuit-switched era, won't be able to efficiently support mass-market, real-time IP services in the medium term. With the shift to lower-latency flat networks that comprise fewer network nodes, mobile operators can align infrastructure capabilities with emerging application requirements and benefit from substantially greater flexibility in how core and access networks are integrated.

At a high level, there's remarkable agreement about what the next-generation IP network architecture should look like: base station router products interconnected by IP/Ethernet, deployed in a flat user-plane architecture, with services provisioned and managed by an IMS control plane.

Key to the emergence of flat networks is advanced base station equipment that integrates functions such as radio control, header compression, encryption, call admission control, and policy enforcement. In the mobile core, the requirement is for "access gateway" products capable of supporting multiple radio technologies simultaneously on a common hardware and software platform, scaleable to multiple cost and traffic profiles.

Getting to that point is the challenge. With differing visions of how the migration should occur, industry participants are investigating the relative benefits of what are sometimes called "maximally-flat" and "semi-flat" architectures – depending on how many distinct pieces of equipment should be removed from, or retained in, the network. In this context, the Insider report identifies five key technology paths to the flat, all-IP mobile network:

• Base Station Routers: These are products that collapse the functions of today's hierarchal architectures into integrated base station devices. Initially, the intent is to overlay existing networks in micro-, pico-, and femtocell applications, with macrocell deployments perhaps coming in late 2008. Vendors here include Alcatel-Lucent (NYSE: ALU), Airvana Inc. (Nasdaq: AIRV), and femtocell players such as Ubiquisys Ltd.

• Direct Tunnel Architecture: This is emerging as the most viable evolution for Wideband CDMA macro networks and is aligned with the introduction of Evolved HSPA radio interfaces. Example implementations include the "Internet HSPA" initiative from Nokia Siemens Networks and the SGSN bypass architecture from Ericsson AB (Nasdaq: ERIC).

• WiMax Access Services Network: This is the first standardized IP-centric mobile network, establishing principles now being adopted across the industry. Vendors active in developing this architecture and profiled in the report include Alvarion Ltd. (Nasdaq: ALVR), Motorola Inc. (NYSE: MOT), Nortel Networks Ltd. , and Samsung Electronics Co. Ltd. (Korea: SEC).

• System Architecture Evolution: An all-IP architecture linked to emerging orthogonal frequency-division multiple access (OFDMA) radio specifications, defined by the 3rd Generation Partnership Project (3GPP) . It seems likely that this will ultimately emerge as the dominant mobile network architecture. All the major vendors are present here, with some, such as Huawei Technologies Co. Ltd. , explicitly linking today's WiMax R&D initiatives with future 3GPP requirements.

• Ultra Mobile Broadband: Defines the Converged Access Network architecture for the 3rd Generation Partnership Project 2 (3GPP2) . With specifications due for completion in October 2007, this aggressive schedule maintains the CDMA community's reputation for moving quickly through the standards process. The question is, how much backing is there for this initiative?

Naturally, this migration to flat IP architectures opens up substantial opportunities for router vendors. Cisco Systems Inc. (Nasdaq: CSCO), for example, is involved with all the major 3G and 4G initiatives and looks set to emerge as leading supplier of access services network (ASN) gateways to WiMax operators. Juniper Networks Inc. (Nasdaq: JNPR) is pursing a "unified mobile edge" strategy that will see it partner with major radio suppliers to provide key expertise in IP security and policy management. And specialist mobile core supplier Starent Networks Corp. (Nasdaq: STAR) is currently the only provider with a convincing common platform story for multi-standard access gateways.

— Gabriel Brown, Chief Analyst, Unstrung Insider

The report, Flat IP Architectures for Mobile Networks, is available as part of an annual subscription (12 monthly issues) to Unstrung Insider, priced at $1,595. Individual reports are available for $900. To subscribe, please visit: www.unstrung.com/insider.