Before the Federal Communications Commission Washington, D.C

Before the Federal Communications Commission Washington, D.C. 20554

In the Matter of ) Wireless Broadband Access ) GN Docket No. 04-163 )

REPLY COMMENTS OF IPWIRELESS, INC.

IPWireless, Inc. (“IPWireless” or “IPW”) respectfully responds to the initial comments filed by other interested parties in response to the to the Public Notice issued May 4, 2004 seeking public input to the Commission’s Wireless Broadband Access Task Force (“Task

Force”).1 In these brief reply comments, IPWireless will address three specific issues: 1) the

need for internationally harmonized frequency allocations, including allocations of unpaired

spectrum for TDD use, to facilitate the provision of services to roamers; 2) the inherent spectral

efficiency of TDD technology, particularly for generally asymmetric data applications such as

web browsing and streaming media; and 3) the imminent commercial deployment of High Speed

Downlink Packet Access (“HSDPA”) on the IPWireless UMTS TDD platform. This will occur

months, if not years, in advance of the anticipated commercial availability of HSDPA on the

UMTS FDD technology platform.

1. Internationally Harmonized Spectrum. In IPWireless’ June 3, 2004 Comments, at pp.

5-15, we noted that broadband wireless access has been introduced by licensed operators in

numerous countries in Europe, Africa and the Pacific Rim, using unpaired spectrum in one of

1 Public Notice, GN Docket No. 04-163, “Wireless Broadband Access Task Force Seeks Public Comment on Issues Related to Commission’s Wireless Broadband Policies” (DA 04-1266), rel. May 5, 2004.

several alternative band plans adopted by the ITU for third generation wireless services. We suggested that the Task Force recommend that the Commission jump-start the commercial introduction of licensed broadband wireless access in the United States by designating 1910-

1920 MHz and 2020-2025 MHz for TDD operation, noting that these particular bands are widely used for UMTS TDD services internationally, and would facilitate global roaming.2 Several

other parties commented on the desirability of spectrum harmonization. See, e.g., Comments of the Telecommunications Industry Association (“TIA”) at 4-5, noting the benefits of increased economies of scale and competition, including earlier market availability, larger product variety and greater penetration – all in addition to roaming – that can result when vendors compete in large spectrum-harmonized markets. See also Comments of Motorola, Inc. at 3;3 Comments of

Alvarion at 6.4

2. Spectrum Efficiency of UMTS TDD. Both IPWireless5 and the Global UMTS TDD

Alliance noted in initial comments that UMTS TDD supports the asymmetric nature of

interactive data transmission in a far more frequency-efficient manner than paired-spectrum

technologies such as W-CDMA (FDD). Other parties either overtly or tacitly recognize that TDD

technologies are substantially more efficient than FDD technologies, particularly given the

2 IPWireless also advocated that the Commission identify and award licenses for an additional ten MHz of unpaired spectrum from the 2155-2180 MHz band. The total of 25 MHz of unpaired spectrum, if dedicated to TDD use, could provide sufficient spectrum for up to five operators with 5 MHz each. IPWireless Comments, at 15.

3 “Global harmonization significantly increases the market scale, lowers costs for end users and provides greater opportunities for global interoperability and roaming.”

4 “One major incentive that would apply across both licensed and unlicensed bands would be rules and allocations more consistent with other major regulatory regimes. Many excellent technologies and systems exist and are being deployed in other regions, but not in the U.S. The major example is 3.5 GHz, but others exist as well….”

5 IPWireless Comments at 3; Global UMTS TDD Alliance at 2-3.

typical asymmetry of data flows in applications such as web browsing and file downloads.6 The relative inefficiency of FDD technologies is aptly illustrated by comparing the minimum7 and

anticipated8 spectrum requirements of Cingular, a proponent of UMTS FDD technology, with

IPWireless’ statement that 25 MHz of unpaired TDD spectrum could support up to five

operators.9 Cingular has stated, in its comments in this proceeding and in the materials submitted in support of its proposed merger with AT&T Wireless,10 that – wholly apart from any spectrum

required by its competitors – Cingular will need 30 MHz of paired spectrum to meet its

subscribers’ demand for 3G services in at least some of its markets. By comparison, even at

relatively high levels of demand for 3G services, 30 MHz of unpaired spectrum would be fully

adequate to support two or three TDD operators (vs. only one FDD operator).11 In summary,

compared with continued adherence to the Commission’s traditional approach of licensing commercial mobile spectrum on a paired basis, the dedication of a significant quantity of spectrum to unpaired use provides opportunities for more competition as well as improved spectrum efficiency.

6 Alvarion at 8: “Traffic remains bursty and asymmetric, with higher downstream rates. One effect is that FDD systems may be seen as inefficient use of spectrum where traffic is mostly for Internet data applications.”

7 Cingular at 6: “To deploy UMTS [FDD], a minimum of 10 MHz of dedicated spectrum (5 MHz uplink paired with 5 MHz downlink) must be set aside.”

8 Cingular at 7: “Cingular anticipates that three 10 MHz UMTS spectrum blocks – for a total of 30 MHz – will be necessary to meet anticipated demand for 3G services in most areas.”

9 IPWireless at 15.

10 Declaration of William Hogg and Mark Austin, Attachment 2 to the FCC Form 603 application filed March 18, 2004 in WT Docket No. 04-70, at p. 11.

3. High Speed Downlink Packet Access (“HSDPA”). CTIA, at 5-6, notes that Cingular and AT&T Wireless are planning to migrate to UMTS [FDD], with the potential, once upgraded with High Speed Downlink Packet Access (“HSDPA”) for data transmission at speeds up to 14.4 mbps, and that Qualcomm has announced a chipset solution capable of peak data rates of 7.2 mbps in support of advanced data services for HSDPA. Although such data rates are impressive,

IPWireless understands, based on its discussions with European operators, that commercial deployment is several years in the future. In contrast, IPWireless expects that it will include key elements of HSDPA in a commercial release slated for early third quarter 2004.

HSDPA is part of the 3GPP standard for both W-CDMA [FDD] and UMTS TDD. When applied to UMTS TDD, the peak sector rates are similar to those in W-CDMA with HSDPA, but

UMTS TDD delivers substantially higher average throughput across the sector, and higher cell edge throughput. For example, the commercial deployment at UK Broadband delivers a minimum of 1 megabit per second at the cell edge. In the W-CDMA implementation, the packet-switched HSDPA feature is only applied to the downlink; the uplink (mobile to base) remains circuit switched. The circuit-switched uplink is a severe capacity constraint on the system. By contrast, in UMTS TDD (as implemented by IPWireless, for example) both the uplink and the downlink are packet based. This means that the uplink is not a constraint on system capacity, leading to the capability to support more than 10 times the number of users in the same amount of spectrum. Additionally, in UMTS TDD, the capacity gains derived from

HSDPA can be applied to the uplink, by changing the timeslot allocation.

Whereas circuit switched FDD systems are inherently inflexible, UMTS TDD technology can be adapted to changing traffic upstream and downstream patterns over time, and can even be adapted to operate in paired spectrum, where only paired spectrum is available. For instance, a

cellular or PCS licensee in a less densely populated market may have a pair of 5 MHz channels that are underutilized and desire to meet the market demand for broadband wireless access. Such a licensee could utilize UMTS TDD technology, taking advantage of the “auxiliary downlink” capability developed and marketed by IPWireless to double the total capacity compared to a single unpaired channel, and deliver average sector throughput 3 – 4 times higher than W-

CDMA/HSDPA in the same spectrum. Such an implementation allows high data rate broadband service to be delivered to rural communities using unused PCS or cellular spectrum. This further illustrates the inherent adaptability of UMTS TDD, as compared with FDD W-CDMA, where the uplink/downlink symmetry is fixed and inflexible.

Conclusion

I Wireless appreciates the opportunity afforded by the Commission to present its views

and recommendations regarding wireless broadband access, and looks forward to working with

the members of the Task Force as they develop recommendations for the Commission.

Respectfully submitted, IPWireless, Inc.

By: /s/ Larry A. Blosser______Larry A. Blosser ([email protected]) Gray Cary Ware & Freidenrich LLP 1625 Massachusetts Avenue, N.W. Suite 300 Washington, D.C. 20036 Tel: 202-238-7700

Counsel for IPWireless, Inc. Dated: July 1, 2004