By Steve Metcalf
Television news remains firmly under state control
State domination of Iran's media has been undermined in recent years as Iranians increasingly turn to the internet and satellite TV channels run by Iranians abroad.
Viewers with satellite dishes can tune into a host of channels run by expatriate Iranians, with 20 of them based in California alone, mostly in the Los Angeles area. Although possession of a satellite dish is technically illegal in Iran, the ban is only sporadically enforced.
Some of these exile stations are explicitly opposed to the government in Tehran, but most simply offer Western-style entertainment and talk shows that are not available on state-run TV.
They also offer a distinct take on the news, as state TV will not broadcast anything critical of the ruling establishment.
War of the blogs
There are now more than 100,000 active blogs in Iran
A profusion of news websites and blogs is matched only by the government's efforts to control cyberspace.
After English, Farsi is now one of the most widely-used languages in the "blogosphere". There are said to be over 100,000 active weblogs by Iranians. Even politicians, including one former vice-president, have got in on the act.
The government has responded by taking action against individual bloggers, as well as trying to filter and block access to websites it objects to.
Officials have spoken of plans to set up a "national" internet, effectively an intranet, enabling them to have more effective control of access to the wider, global internet.
There has also been an explosion in the number of news websites, many of them associated with the conservative end of the political spectrum.
Within Iran, the broadcast media are firmly under state control. No private channels are allowed. The state broadcaster runs eight TV channels and eight radio networks, plus a number of provincial and international channels.
Its director-general is personally appointed by the supreme leader, Ayatollah Ali Khamenei.
Some foreign films and documentaries are shown, but most TV programmes are domestically produced, covering a wide range of genres, but with a noticeable absence of musical entertainment and videos.
President Mahmoud Ahmadinejad has made known his opposition to the use of "banal and Western" music and the need to promote Islamic values.
The quality of the presentation has improved in recent years, with state-of-the-art graphics and slick studio sets. But all female presenters still wear the traditional chador, or head-covering, and there are regular breaks to broadcast daily prayers.
Even the occasional mildly satirical programme attracts the ire of the conservatives.
This recently prompted a defeated presidential candidate to try and set up a TV channel broadcasting out of Dubai. But the plan fell through after strenuous pressure from Tehran.
Journalists under fire
Sports newspapers far outsell political dailies
The newspaper industry burgeoned in the 1990s, especially under the first presidency of Mohammad Khatami (1997-2001), and there was a short period of relative press freedom.
But the judicial authorities stepped in and forced the closure of over 100 publications, many of which took a more liberal or reformist line.
More recently, the authorities have tended to take action against individual journalists rather than publications. In November 2005, Reporters Without Borders called for an end to the harassment and intimidation of journalists.
The press freedom watchdog said that at least 10 journalists had been interrogated and advised not to write articles critical of the government. In particular, they were warned against writing about sensitive issues such as Iran's nuclear programme.
Newspapers also face difficulties because of falling readership and a decline in advertising revenue. Although editions of popular sports dailies may sell over a million copies, political dailies have a circulation of a few hundred thousand at most.
The difficulties facing the Iranian media are illustrated by the recent case of a young female journalist on a provincial newspaper.
Searching the internet for material for an article for the health pages, she copied and pasted something about AIDS from the weblog of an expatriate Iranian.
Unfortunately, this was a satirical piece which made unflattering comparisons between AIDS and the deceased leader of the revolution, Ayatollah Khomeini.
The paper has since been closed, its director jailed, and the young journalist is still in prison awaiting trial.
BBC Monitoring selects and translates news from radio, television, press, news agencies and the internet from 150 countries in more than 70 languages. It is based in Caversham, UK, and has several bureaux abroad.