Shares in Alternative Networks (LSE: AN) have risen by around 5% today after the communications services provider released a rather mixed trading update. Although it confirmed that it’s on track to meet its guidance for the full year, performance within the company’s divisions has been markedly different.

While its Advanced Solutions division delivered growth in recurring revenues and has ended the half year with a strong backlog of non-recurring business, the challenging markets in the company’s Mobile division have persisted. Specifically, the impact of new tariffs on roaming rates has offset further gains in market share, but with cash flow being strong and the overall performance of the business being encouraging, Alternative Networks continues to offer a bright long-term future.

With the company forecast to increase its bottom line by 13% next year, investor sentiment in Alternative Networks could improve. And while it’s experiencing a difficult period, its price-to-earnings-growth (PEG) ratio of 0.8 indicates that there’s a sufficiently wide margin of safety to merit purchase at the present time.

Talk is cheap

Also suffering from a challenging period within the telecoms space is Talktalk (LSE: TALK), with the company not yet fully recovering from the hacking scandal of last year. Clearly, it hurt investor sentiment and Talktalk’s share price hasn’t yet recovered the ground it lost last year, although it has risen by an impressive 14% since the turn of the year.

Although there’s likely to be a significant impact on new customer growth and on customer retention from the hacking scandal, Talktalk’s outlook remains positive. That’s at least partly because it offers a relatively wide margin of safety, with its shares trading on a PEG ratio of just 0.5 at the present time. Certainly, there’s increasing competition within the quad-play space, but with Talktalk having a sound business model and an excellent track record of growth, it seems to be a worthy purchase for the long term.

Fighting back

Meanwhile, Vodafone (LSE: VOD) has also struggled in recent years, with the telecoms major being hurt by a slowdown in the European economy. While this has dragged on its share price performance, Vodafone seems to have excellent growth prospects. For example, it’s expected to increase its earnings by 22% this year and by a further 30% next year.

This appears to be a direct result of Vodafone’s strategy to invest heavily in its network and diversify into new product areas such as pay-TV. Buying undervalued European assets such as Spain’s Ono and Kabel Deutschland also seems to have been a sound long-term move. And although a European downturn could hurt Vodafone’s outlook, its dividend yield of 5% indicates that it offers a sufficiently wide margin of safety to merit investment right now.

And due to its size and scale, it appears to be a better buy than Alternative Networks or Talktalk, although they still offer excellent long-term prospects, too.

Of course, finding stocks that are worth adding to your portfolio is a tough task, which is why the analysts at The Motley Fool have written a free and without obligation guide called 10 Steps To Making A Million In The Market.

It's a simple and straightforward guide that could make a real difference to your portfolio returns. As such, 2016 could prove to be an even better year than you had thought possible.

Click here to get your copy of the guide - it's completely free and comes without any obligation.

Peter Stephens owns shares of Alternative Networks, TalkTalk Telecom Group plc, and Vodafone. The Motley Fool UK has no position in any of the shares mentioned. We Fools don't all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors.