Talk:High-Speed Downlink Packet Access/Archive 1

Slow power control?

'The High-Speed Downlink Shared Channel (HS-DSCH) lacks two basic features of
other W-CDMA channels — variable spreading factor and fast power control ...'

1. The channel is estimated 500 times per sec and this information is fed back to the Node B. Is this information not used for power control?

2. Why is good to have a variable spreading factor?

Cheers, MatthiasH (talk) 16:29, 18 November 2008 (UTC)

1. No, at least not in the way power control is used in the uplink and for legacy UMTS channels. The scheduler typically allocates a fixed amount of power to HSDPA channels. Instead, the number of multicodes, the modulation scheme and the code rate are adapted to the channel. Each of those parameters trade energy per bit for data rate. Only when lower categories report a very high channel quality the base station may choose to reduce power, because the device has already reached its maximum supported data rate.
2. A variable spreading factor works just like a variable number of codes (multicodes). A low spreading factor increases the data rate but reduces the energy per bit. --Drizzd (talk) 08:24, 24 June 2011 (UTC)

Is it a GSM or CDMA or other?

I'm confused. Is this in the GSM or the CDMA family. (i.e. as an ordinary person, is it AT&T/Cingular/T-Mobile/whatever or Sprint/Credo/whatever?). Or is it something else and incompatible with existing cell networks? --Treekids (talk) 18:03, 19 February 2008 (UTC)

HSDPA uses CDMA. Not sure what you mean with compatible but you can not decode a HSDPA-signal with a unmodified UMTS receiver. But it is possible to extend existing networks to support as well HSDPA as UMTS. MatthiasH (talk) 16:29, 18 November 2008 (UTC)

HSDPA uses Wideband CDMA and is part of the 3G specification of the GSM family (i.e. 3GPP), whereas the CDMA family is part of the 3GPP2/North american standardization bodies. However nowadays WCDMA-based networks are common in the US as well (at least AT&T and TMobile). Nasula (talk) 20:08, 2 March 2012 (UTC)

Meaningless sentence

Chaps & chapesses, the sentence:

'HSDPA provides a smooth evolutionary path for Universal Mobile 
Telecommunications System (UMTS) networks jack is a rates and 
higher capacities.' 

is absolutely meaningless! dutchdavey 18Apr2006

I have no idea what's going on here. Twinxor 09:03, 8 Feb 2005 (UTC)

Adoption

I don't really think the Adoption section is meaningful anymore, HSDPA networks and WAN using them have become pretty mainstream everywhere, you can't list all the phones. Notebooks seem to be less notable, and so does the rest. It would be better to just update the List of Deployed HSDPA networks. 1wonjae 04:56, 15 October 2007 (UTC)

Laptops

The sentence: 'Dell began releasing, in June 2006, laptops with in-built HSDPA chips from Vodafone, ...' etc.

is misleading. Vodafone does not manufacture chips at all. They sell OEMed data-cards and modules from Option and others.

20Mbps

I think HSDPA can reach 20Mbps when 64-QAM is used, not necessary for MIMO.

More Slow

Especially considering that KDDI's CDMA2000 is generally considered as being much more successful and smooth than DoCoMo's and Vodafone's UMTS / wCDMA introduction in Japan, which are much more slow than initially hoped.

Which is slower (more slow), deployment or data network throughput?

Copyright Violation?

The first two paragraphs are copied verbatim from http://www.umtsworld.com/technology/hsdpa.htm which http://www.umtsworld.com/umts/legal.htm claims is umtsworld's property. Haven't looked further, so it is possible that umtsworld took it from (for example) the standards themselves, and have just forgot to reference their own source. Regardless, probably needs clarifying.

I removed the copyrighted material. It was inserted by 208.25.178.242 on 11/18/04. I replaced it with the introduction from the edit before that. -- Kjkolb 00:43, 8 February 2006 (UTC)

First HSDPA network?

I´ve read this

http://www.3g.co.uk/PR/Feb2006/2683.htm

and apparently there´s already an HSDPA network... in Portugal, EU... An update to the article in wikipedia?

Thank you.

Bold text== Phones ==

• Samsung SGH-Z560

What is it with this??

Deployment

I think it's time we moved the deployment-stuff to it's own article by now. After all, you don't see all the hundreds of different GSM/3G networks listed under their respective articles. Leave only some basic info like the first network, current fastest one, number of networks in place atm, etc. How do u guys think? --Darin-0 22:45, 27 November 2006 (UTC)

I agree. I have to say that people are going over the top with lists of deployments in most articles concerning mobile technologies. I don't mind there being something articles entitled "List of operators that have deployed X" but it's somewhat long and makes it harder to navigate when it's incorporated into the main article. Squiggleslash 22:56, 27 November 2006 (UTC)

Acronym

Various sources state the acronym HSPDA stands for High Speed Download Packet Access, High Speed Data Packet Access, and even High Speed Download Packet Applications, in addition to High-Speed Downlink Packet Access as is it written in this article. Makes me think of DSL (digital subscriber loop/line) or ISDN (Integriertes Sprach- und Datennetz/Integrated Speech and Data Net/Integrated Services Digital Network). Not sure if the variations above (and possible others) are worth mentioning here? ntennis 00:42, 25 September 2007 (UTC)

I agree with High Speed Data Packet Access. Because we also commonly known this connection as High Speed Data Packet Access. ʂaɳɖaƙɘɭʉɱ ^ʈaɭƙ 06:12, 22 September 2012 (UTC)

3.5G

3.5G redirects here but isn't explained. —Preceding unsigned comment added by 87.162.9.8 (talk) 16:44, 4 October 2007 (UTC)

I changed the redirect of 3.5G to point to Beyond 3G. Some sources do refer to HSDPA as 3.5G, perhaps this article should mention it. Mathiastck (talk) 18:12, 11 April 2008 (UTC)

Someone changed the redirect of 3.5G back to point to HSDPA, but since 3.5G is not mentioned there, I changed it to point to 3.5G#Wireless System Evolution, where it is discussed. According to that section, 3.5G may not only refer to HSDPA, but also to HSUPA (which 3.75G also is redirected to) and Evolved HSPA (HSPA+). If this is not true, please correct it.

The redirect is also discussed at Talk:4G#What to do about the removed "Beyond 3G", "3.5G" and "5G" articles. Mange01 (talk) 08:47, 29 July 2008 (UTC)

Latency

The sentence "As well as improving data rates, HSDPA also increases latency (engineering) and so the round trip time for applications.", under improvements, doesn't make much sense.

Either the latency has been *decreased* (and so the round trip) or it's not an improvement at all. —Preceding unsigned comment added by 84.248.110.245 (talk) 19:41, 10 November 2008 (UTC)

From reading the rest of the article, I think it is reasonable to infer that the improvements such as fast packet scheduling would serve to decrease latency. Changed to 'decreases' but expert attention would be nice. —Preceding unsigned comment added by 68.209.229.218 (talk) 05:25, 25 December 2008 (UTC)

After further reading, the sentence is correct with 'decreases' in place of 'increases.'

In all, the datarate has increased seven-fold, the response time has reduced by 80% and the algorithms, scheduling and complexity have increased dramatically.

- From [1]

Without proof (measurements etc), this sentence is wrong, misleading and lacks citation. --Ltsampros2 (talk) 10:20, 21 January 2011 (UTC)

SIM access profiles (SAP): Why no *HSPA modem* access ?!

Please note the thread I initiated at

http://en.wikipedia.org/wiki/Talk:Bluetooth_profile#SIM_access_profiles_.28SAP.29:_Why_no_.2AHSPA_modem.2A_access_.3F.21 .

In other words, it is number 16 there, showing the title above. —Preceding unsigned comment added by 70.32.33.163 (talk) 12:16, 27 October 2010 (UTC)

User equipment categories

The table for categories 15-28 does not make sense to me when compared with table 5.1a from the ETSI standard. Someone with a better understanding please calculate data rates. --Dmitry _{(talk•contibs)} 22:05, 1 February 2012 (UTC)

For Categories 28 and above, basically you can take Cat 14 as a reference and multiply by 2 for MIMO and by the number of cells for multi-cell. --Drizzd (talk) 23:25, 14 February 2012 (UTC)