????覆蓋范圍不是唯一拖累5G發(fā)展的問(wèn)題，另一個(gè)問(wèn)題是什么？頻譜資源有限，這在美國(guó)已經(jīng)是一個(gè)相當(dāng)嚴(yán)重的問(wèn)題。“如果由于網(wǎng)絡(luò)負(fù)載飽和而變慢，從而拖累5G，會(huì)怎樣呢？”席爾瓦問(wèn)道，“美國(guó)是否能提供更多光譜以滿足數(shù)據(jù)使用需求還是個(gè)問(wèn)題。另外一個(gè)問(wèn)題是運(yùn)營(yíng)商的流量限制，如果能在幾分鐘內(nèi)接收一部電影，消費(fèi)者將很快用完流量額度。”

????要使5G成為現(xiàn)實(shí)，這只是其中幾個(gè)需要解決的問(wèn)題。更大的難題在于目前還沒(méi)有既定標(biāo)準(zhǔn)，即使著手制定，也不是一朝一夕的事。“無(wú)論是有線或無(wú)線，技術(shù)人員都在不斷努力提升寬帶速度，”席爾瓦說(shuō)道，“但這不是動(dòng)動(dòng)手指就能解決的。我們也不知道其他公司的藍(lán)圖上有怎樣的規(guī)劃。在商定標(biāo)準(zhǔn)之前，仍有許多方面需要充實(shí)完善，許多尚未到位的內(nèi)容要及時(shí)敲定。”

????另一方面，這也使得2020年這一截止期顯得不那么現(xiàn)實(shí)。不過(guò)，全球移動(dòng)通信系統(tǒng)（GSM）于1990年推出后，2003年便出現(xiàn)了3G，2009年4G也隨之到來(lái)。從某些方面說(shuō)，這一技術(shù)的開(kāi)發(fā)已經(jīng)出現(xiàn)了一定的競(jìng)爭(zhēng)態(tài)勢(shì)，中國(guó)已成立由政府牽頭的“IMT-2020 (5G) 推進(jìn)組”，專門(mén)致力于5G研發(fā)，而歐盟委員會(huì)也宣布計(jì)劃于2013年投資5000萬(wàn)歐元，以期在2020年將5G推向市場(chǎng)。根據(jù)這個(gè)時(shí)間表，以及全球廠商對(duì)這一技術(shù)的關(guān)注，5G很可能在10年內(nèi)實(shí)現(xiàn)，但問(wèn)題猶存。

????“許多國(guó)家的問(wèn)題是，連推出4G都面臨一些宏觀層面的難題，”格林森補(bǔ)充道，“幾年內(nèi)可能還無(wú)法將5G投入商用，不過(guò)目前一切還只是推測(cè)。因?yàn)槲覀儫o(wú)法預(yù)知今后10年的經(jīng)濟(jì)形勢(shì)和技術(shù)發(fā)展。還有太多問(wèn)題仍待解決。”（財(cái)富中文網(wǎng)）

????譯者：默默

????Range won't be the only issue that could be a stalling point for 5G. The other? Spectrum limitations, already a significant problem in the United States. "What happens if 5G is compromised because of slowdowns due to network capacity?" asks Silva. "There is still the question as whether the United States can make available more spectrum to accommodate the data usage. There is also the issue of how carriers today have data caps, and if streaming a movie in a few minutes is an option, consumers could reach those data caps rather quickly."

????Those are just a few problems that will need to be addressed as 5G becomes a reality. The bigger issue is that there is still no set standard and won't likely be one for some time. "There are constant efforts to make broadband faster whether it is through the wirelines or wireless," says Silva. "But you can't just snap your fingers and make it happen. We also don't know what is on the drawing boards of other companies. Until the standards are agreed upon. there is still a lot to flesh out, with a lot of moving parts that will play out in time."

????On the one hand this makes a possible deadline of 2020 seem unlikely, but GSM came out in the 1990s, following by 3G in 2003, with 4G arriving in 2009. In some ways there is already a race in progress to develop the technology, as China has established a government-led "IMT-2020 (5G) Promotion Group" specifically for 5G research, while the European Commission has also announced plans to invest 50 million euros in 2013 to bring 5G to market by 2020. Given this timetable, as well as the international interest in the technology, it is quite likely that 5G could arrive in the next decade, but issues do remain.

????"The problem for many countries is that on the macro level there are still difficulties in rolling out 4G," adds Gleeson. "A commercial launch of 5G thus might not come for years; it is just speculation at the moment. For one we don't know how the economy will fare or how the technology will actually develop over the next 10 years. There are just too many unanswered questions."